<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
   targetNamespace="http://impex-fp7.oeaw.ac.at" xmlns="http://impex-fp7.oeaw.ac.at"
   elementFormDefault="qualified">

   <xsd:element name="Spase" type="Spase"/>
   <xsd:complexType name="Spase">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Space Physics Archive Search and Extract (SPASE).
               The outermost container or envelope for SPASE
               metadata. This indicates the start of the
               SPASE metadata.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Version" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceEntity" minOccurs="1" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:attribute name="lang" type="xsd:string" default="en"/>
   </xsd:complexType>

   <xsd:element name="ResourceEntity" abstract="true"/>

   <xsd:element name="Catalog" type="Catalog" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Catalog">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A tabular listing of events or observational
               notes, especially those that have utility
               in aiding a user in locating data. Catalogues
               include lists of events, files in a product,
               and data availability. A Catalog resource
               is a type of "data product" which is a set
               of data that is uniformly processed and formatted,
               from one or more instruments, typically spanning
               the full duration of the observations of the
               relevant instrument(s). A data product may
               consist of a collection of granules of successive
               time spans, but may be a single high-level
               entity.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessInformation" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="ProviderResourceName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderVersion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="InstrumentID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="PhenomenonType" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="TimeSpan" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Keyword" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="InputResourceID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Parameter" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="ResourceHeader" type="ResourceHeader"/>
   <xsd:complexType name="ResourceHeader">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Attributes of a resource which pertain to
               the provider of the resource and descriptive
               information about the resource.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceName" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AlternateName" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ReleaseDate" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ExpirationDate" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Acknowledgement" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Contact" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="InformationURL" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Association" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="PriorID" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Contact" type="Contact"/>
   <xsd:complexType name="Contact">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The person or organization who may be able
               to provide special assistance or serve as
               a channel for communication for additional
               information about a resource.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="PersonID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Role" minOccurs="1" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="InformationURL" type="InformationURL"/>
   <xsd:complexType name="InformationURL">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Attributes of the method of acquiring additional
               information.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="URL" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Language" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Association" type="Association"/>
   <xsd:complexType name="Association">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Attributes of a relationship a resource has
               with another resource.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="AssociationID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AssociationType" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Note" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="AccessInformation" type="AccessInformation"/>
   <xsd:complexType name="AccessInformation">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Attributes of the resource which pertain to
               how to accessing the resource, availability
               and storage format.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="RepositoryID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Availability" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="AccessRights" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="AccessURL" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="Format" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Encoding" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="DataExtent" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Acknowledgement" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="AccessURL" type="AccessURL"/>
   <xsd:complexType name="AccessURL">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Attributes of the method for accessing a resource
               including a URL, name and description.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="URL" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ProductKey" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Language" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="DataExtent" type="DataExtent"/>
   <xsd:complexType name="DataExtent">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The area of storage in a file system required
               to store the contents of a resource. The default
               units for data extent is bytes.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Quantity" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Per" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="TimeSpan" type="TimeSpan"/>
   <xsd:complexType name="TimeSpan">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The duration of an interval in time.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="StartDate" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="StopDateEntity" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Note" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="StopDateEntity" abstract="true"/>

   <xsd:element name="Parameter" type="Parameter"/>
   <xsd:complexType name="Parameter">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A container of information regarding a parameter
               whose values are part of the product. Every
               product contains or can be related to one
               or more parameters.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Set" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ParameterKey" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Cadence" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="UnitsConversion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="CoordinateSystem" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="RenderingHints" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Structure" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValidMin" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValidMax" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="FillValue" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ParameterEntity" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Property" maxOccurs="unbounded" minOccurs="0"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="ParameterEntity" abstract="true"/>

   <xsd:element name="CoordinateSystem" type="CoordinateSystem"/>
   <xsd:complexType name="CoordinateSystem">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The specification of the orientation of a
               set of (typically) orthogonal base axes.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="CoordinateRepresentation" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="CoordinateSystemName" minOccurs="1" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="RenderingHints" type="RenderingHints"/>
   <xsd:complexType name="RenderingHints">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Attributes to aid in the rendering of parameter.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="DisplayType" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="AxisLabel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="RenderingAxis" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Index" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValueFormat" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ScaleMin" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ScaleMax" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ScaleType" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Structure" type="Structure"/>
   <xsd:complexType name="Structure">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The organization and relationship of individual
               values within a quantity.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Size" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Element" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Element" type="Element"/>
   <xsd:complexType name="Element">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A component or individual unit of a multiple
               value quantity such as an array or vector.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Qualifier" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Index" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ParameterKey" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="UnitsConversion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValidMin" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValidMax" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="FillValue" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="RenderingHints" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Field" type="Field" substitutionGroup="ParameterEntity"/>
   <xsd:complexType name="Field">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The space around a radiating body within which
               its electromagnetic attributes can exert force
               on another similar body that is not in direct
               contact.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Qualifier" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="FieldQuantity" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="FrequencyRange" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="FrequencyRange" type="FrequencyRange"/>
   <xsd:complexType name="FrequencyRange">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The range of possible values for the observed
               frequency.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="SpectralRange" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Low" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="High" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Bin" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Bin" type="Bin"/>
   <xsd:complexType name="Bin">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A grouping of observations according to a
               band or window of a common attribute.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="BandName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Low" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="High" minOccurs="1" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="EnergyRange" type="EnergyRange"/>
   <xsd:complexType name="EnergyRange">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The minimum and maximum energy values of the
               particles represented by a given "physical
               parameter" description.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Low" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="High" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Bin" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="AzimuthalAngleRange" type="AzimuthalAngleRange"/>
   <xsd:complexType name="AzimuthalAngleRange">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The range of possible azimuthal angles for
               a group of energy observations. Default units
               are degrees.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Low" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="High" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Bin" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="PolarAngleRange" type="PolarAngleRange"/>
   <xsd:complexType name="PolarAngleRange">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The range of possible polar angles for a group
               of energy observations. Defaults units are
               degrees.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Low" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="High" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Bin" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Wave" type="Wave" substitutionGroup="ParameterEntity"/>
   <xsd:complexType name="Wave">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Periodic or quasi-periodic (AC) variations
               of physical quantities in time and space,
               capable of propagating or being trapped within
               particular regimes.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="WaveType" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Qualifier" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="WaveQuantity" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="EnergyRange" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="FrequencyRange" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="WavelengthRange" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="WavelengthRange" type="WavelengthRange"/>
   <xsd:complexType name="WavelengthRange">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The range of possible values for the observed
               wavelength.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="SpectralRange" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Low" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="High" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Bin" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Mixed" type="Mixed" substitutionGroup="ParameterEntity"/>
   <xsd:complexType name="Mixed">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A parameter derived from more than one of
               the type of parameter. For example, plasma
               beta, the ratio of plasma particle energy
               density to the energy density of the magnetic
               field permeating the plasma, is "mixed."
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="MixedQuantity" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ParticleType" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Qualifier" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Support" type="Support" substitutionGroup="ParameterEntity"/>
   <xsd:complexType name="Support">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Information useful in understanding the context
               of an observation, typically observed or measured
               coincidentally with a physical observation.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Qualifier" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="SupportQuantity" minOccurs="1" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Extension" type="Extension"/>
   <xsd:complexType name="Extension">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A container of other metadata which is not
               part of the SPASE data model. The contents
               of this element are defined by individual
               usage. The organization and content are constrained
               by the implementation. For example, in an
               XML representation of the SPASE metadata the
               content must conform to the XML specifications.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:any minOccurs="0"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="DisplayData" type="DisplayData" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="DisplayData">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A graphical representation of data wherein
               the underlying numeric values are not (readily)
               accessible for analysis.. Examples are line
               plots and spectrograms. A Display Data resource
               is a type of "data product" which is a set
               of data that is uniformly processed and formatted,
               from one or more instruments, typically spanning
               the full duration of the observations of the
               relevant instrument(s). A data product may
               consist of a collection of granules of successive
               time spans, but may be a single high-level
               entity.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessInformation" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="ProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderResourceName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderVersion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="InstrumentID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="MeasurementType" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="TemporalDescription" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SpectralRange" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="DisplayCadence" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ObservedRegion" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Keyword" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="InputResourceID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Parameter" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="TemporalDescription" type="TemporalDescription"/>
   <xsd:complexType name="TemporalDescription">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the time over which
               the measurement was taken.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="TimeSpan" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Cadence" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Exposure" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="NumericalData" type="NumericalData" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="NumericalData">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Data stored as numerical values in a specified
               format. A Numerical Data resource is a type
               of "data product" which is a set of data that
               is uniformly processed and formatted, from
               one or more instruments, typically spanning
               the full duration of the observations of the
               relevant instrument(s). A data product may
               consist of a collection of granules of successive
               time spans, but may be a single high-level
               entity.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessInformation" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="ProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderResourceName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderVersion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="InstrumentID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="MeasurementType" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="TemporalDescription" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SpectralRange" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ObservedRegion" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Keyword" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="InputResourceID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Parameter" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Document" type="Document" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Document">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A set of information designed and presented
               as an individual entity. A document may contain
               plain or formatted text, in-line graphics,
               sound, other multimedia data, or hypermedia
               references. A Document resource is intended
               for use on digital objects that have no other
               identifier (e.g., DOI or ISBN). 
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessInformation" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="Keyword" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="DocumentType" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="MIMEType" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="InputResourceID" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Source" type="Source"/>
   <xsd:complexType name="Source">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The location and attributes of an object.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="SourceType" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="URL" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="MirrorURL" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Checksum" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="DataExtent" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Checksum" type="Checksum"/>
   <xsd:complexType name="Checksum">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A computed value that is dependent upon the
               contents of a digital data object. Primarily
               used to check whether errors or alterations
               have occurred during the transmission or storage
               of a data object.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="HashValue" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="HashFunction" minOccurs="1" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Instrument" type="Instrument" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Instrument">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A device that makes measurements used to characterize
               a physical phenomenon, or a family of like
               devices.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="InstrumentType" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="InvestigationName" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="OperatingSpan" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ObservatoryID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="OperatingSpan" type="OperatingSpan"/>
   <xsd:complexType name="OperatingSpan">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The interval in time from the first point
               at which an instrument or spacecraft was producing
               and sending data until the last such time,
               ignoring possible gaps.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="StartDate" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="StopDate" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Note" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Observatory" type="Observatory" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Observatory">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The host (spacecraft, network, facility) for
               instruments making observations, or a family
               of closely related hosts.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ObservatoryGroupID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Location" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="OperatingSpan" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Location" type="Location"/>
   <xsd:complexType name="Location">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A position in space definable by a regional
               referencing system and geographic coordinates.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ObservatoryRegion" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="CoordinateSystemName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Latitude" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Longitude" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Elevation" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Person" type="Person" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Person">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               An individual human being.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ReleaseDate" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PersonName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="OrganizationName" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Address" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Email" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="PhoneNumber" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="FaxNumber" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Note" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Registry" type="Registry" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Registry">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A location or facility where resources are
               cataloged.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessURL" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Repository" type="Repository" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Repository">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A location or facility where resources are
               stored.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessURL" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Service" type="Service" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Service">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A location or facility that can perform a
               well defined task.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessURL" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="Annotation" type="Annotation" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Annotation">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Information which is explanatory or descriptive
               which is associated with another resource.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ImageURL" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="AnnotationType" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="PhenomenonType" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ClassificationMethod" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ConfidenceRating" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="TimeSpan" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ObservationExtent" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="ObservationExtent" type="ObservationExtent"/>
   <xsd:complexType name="ObservationExtent">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The spatial area encompassed by an observation.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ObservedRegion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="StartLocation" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="StopLocation" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Note" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>
   <!-- ================================
      Dictionary Terms
     ================================ -->
   <xsd:element name="AccessRights" type="enumAccessRights">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Permissions granted or denied by the host
               of a product to allow other users to access
               and use the resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Acknowledgement" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The individual, group or organization which
               should be acknowledged when the data is used
               in or contributes to a presentation or publication.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Address" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Directions for finding some location; written
               on letters or packages that are to be delivered
               to that location.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="AlternateName" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               An alternative or shortened name used to refer
               to a resource. This includes acronyms, expanded
               names or a synonym for a resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="AnnotationType" type="enumAnnotationType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A classification for an annotation.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="AssociationID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The resource identifier for a resource with
               which this resource is closely associated.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="AssociationType" type="enumAssociationType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the role or purpose
               of an associated resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="AtomicNumber" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The number of protons in the nucleus of an
               atom.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Availability" type="enumAvailability">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               An indication of the method or service which
               may be used to access the resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="AxisLabel" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A short character string (approximately 10
               characters, but preferably 6 characters -
               more only if absolutely required for clarity)
               which can be used to label a y-axis for a
               plot or to provide a heading for a data listing.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="BandName" type="xsd:string"/>
   <xsd:simpleType name="BandName">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A common or provider assigned name for a range
               of values.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string"/>
   </xsd:simpleType>
   <xsd:element name="Cadence" type="xsd:duration">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The time interval between the start of successive
               measurements.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Caveats" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Information which may be important in the
               avoidance of the misuse of the resource, for
               instance instrument maladies, corruption or
               contamination.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ClassificationMethod" type="enumClassificationMethod">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The technique used to determine the characteristics
               of an object.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ConfidenceRating" type="enumConfidenceRating">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A classification of the certainty of an assertion.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="CoordinateRepresentation" type="enumCoordinateRepresentation">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The method or form for specifying a given
               point or vector in a given coordinate system.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="CoordinateSystemName" type="enumCoordinateSystemName">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifies the coordinate system in which
               the position, direction or observation has
               been expressed.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Description" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A narrative explanation with detail appropriate
               for the item it describes. For example a description
               of data resource should include discussions
               of the main quantities in the resource, possible
               uses and search terms. A description should
               also include whether any corrections (i.e,
               geometry, inertial) have been applied to the
               resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="DisplayCadence" type="xsd:duration">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The time interval between the successive display
               elements.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="DisplayType" type="enumDisplayType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The general styling or type of plot that is
               suitable for the variable.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="DocumentType" type="enumDocumentType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the content, purpose,
               or style of the document. 
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Elevation" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The distance in meters above (positive) or
               below (negative) the "zero elevation" defined
               by the World Geodetic System reference frame
               (WGS84).
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Email" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The electronic address at which the individual
               may be contacted expressed in the form "local-part@domain".
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Encoding" type="enumEncoding">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A set of unambiguous rules that establishes
               the representation of information within a
               file.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ExpirationDate" type="xsd:dateTime">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The date and time when a resource is no longer
               available. If the Expiration Date is specified
               then it indicates that resource should not
               be made available after that time. However,
               this is only advisory and in practice a resource
               description should be unpublished to eliminate
               access to a resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Exposure" type="xsd:duration">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The time interval over which an individual
               measurement is taken.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="FaxNumber" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The symbols and numerals required to send
               a facsimile (FAX) to an individual by telephone.
               The string may contain punctuation marks such
               as dash (-) or dot (.) to separate fields
               within the string.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="FieldQuantity" type="enumFieldQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The physical attribute of the field.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="FillValue" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A value that indicates that a quantity is
               undefined.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Format" type="enumFormat">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The organization of data according to preset
               specifications. The value is selected from
               a list of accepted names for known, well documented
               formats.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="HashFunction" type="enumHashFunction">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A function or algorithm that converts a digital
               data object into a hash value. Typically the
               hash value is small and concise when compared
               to the digital data object.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="HashValue" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The value calculated by a hash function, e.g.
               the message digest of a digital data object.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="High" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The largest value within a range of possible
               values.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ImageURL" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A URL to graphic, image or movie.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Index" type="typeSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The location of an item in an array or vector.
               An index can be multivalued to represent the
               location in a multidimensional object. The
               index of the first item is "1". A value of
               "0" is a wild card for all elements at the
               location in an array. A value of "-1" is a
               reference to the dimension at the location
               in the array. A "-1" is used when describing
               the attributes of the dimension, where as
               "0" or a positive integer is used to describe
               attributes of individual elements.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="InputResourceID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The resource identifier for a resource which
               was used to generate this resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="InstrumentID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The identifier of an Instrument resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="InstrumentType" type="enumInstrumentType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of an integrated collection
               of software and hardware containing one or
               more sensors and associated controls used
               to produce data on an environment.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="InvestigationName" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The name given to the contract or engagement
               which enabled the data to be produced. Each
               investigation is associated with a Principal
               Investigator or Guest Investigator who was
               responsible for the original proposal. For
               single PI missions each major subsystem having
               its own identified Team Leader may also be
               classed as an "Investigation" for the purposes
               of data archiving.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Keyword" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A word or phrase that is relevant to the resource
               but does not exist in other documentary information.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Language" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The two character indicator of language selected
               from the ISO 630-1 codes for the representation
               of names of languages.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Latitude" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The angular distance north (positive) or south
               (negative) from the equator, measured along
               the meridian passing through the point.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Longitude" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The angular distance measured west (positive)
               or east (negative) from a north-south line
               called the Prime Meridian.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Low" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The smallest value within a range of possible
               values.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="MIMEType" type="xsd:boolean" default="true">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Multipurpose Internet Mail Extensions (MIME)
               type and sub-type which characterizes the
               format of a file. MIME media types are define
               in RFC memorandum RFC 2046. Current MIME types
               are maintained by Internet Assigned Numbers
               Authority (IANA) at http://www.iana.org/assignments/media-types/index.html.
               Commonly used MIME types are: application/vnd.ms-powerpoint
               (ppt, pptx), application/vnd.ms-excel (xls,
               xlsx), text/richtext (rtx), application/postscript
               (eps, ps), application/pdf (pdf), application/xml-dtd
               (dtd), text/html (htm, html), text/xml (xsl,
               xml, xsd), application/x-dvi (dvi). If a document
               is compressed the specified MIME type should
               be for the uncompressed document. 
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="MeasurementType" type="enumMeasurementType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the quantitative assessment
               of a phenomenon.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="MirrorURL" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A Uniform Resource Locator (URL) to an alternate
               location of a resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="MixedQuantity" type="enumMixedQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the combined attributes
               of a quantity.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Name" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A language unit by which a person or thing
               is known.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Note" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Information which is useful or important for
               the understanding of a value or parameter.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ObservatoryGroupID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The identifier of an Observatory resource
               which the referring resource is a member of.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ObservatoryID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The identifier of an Observatory resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ObservatoryRegion" type="enumRegion">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A spatial location distinguished by certain
               natural features or physical characteristics
               where an observatory is located.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ObservedRegion" type="enumRegion">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The portion of space measured by the instrument
               at the time of an observation. A region is
               distinguished by certain natural features
               or physical characteristics. It is the location
               of the observatory for in situ data, the location
               or region sensed by remote sensing observatories
               and the location-of-relevance for parameters
               that are derived from observational data.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="OrganizationName" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A unit within a company or other entity (e.g.,
               Government agency or branch of service) within
               which many projects are managed as a whole.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ParameterKey" type="ParameterKey"/>
   <xsd:simpleType name="ParameterKey">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            The name or identifier which can be used to
            access the parameter in the resource. The
            associated value is dependent on the service
            used to access the resource. For columnar
            ASCII data, use "Column_X" for a single-element
            parameter and "Column_X-Column_Y" for a multi-element
            parameter, where X and Y are the relevant
            column index. The first column index is 1.
         </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string"/>
   </xsd:simpleType>
   <xsd:element name="ParentID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The resource identifier for a resource that
               a resource is a part of. The resource inherits
               the attributes of the referenced resource.
               Attributes defined in the resource override
               attributes of the parent in the manner prescribed
               by the containing resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ParticleQuantity" type="enumParticleQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the physical properties
               of the particle.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ParticleType" type="enumParticleType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the kind of particle
               observed by the measurement.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Per" type="xsd:duration">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The time interval over which a characterization
               applies. For example, the number of bytes
               generated each day.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PersonID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The identifier assigned to a Person description.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PersonName" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The words used to address an individual.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PhenomenonType" type="enumPhenomenonType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The characteristics or categorization of an
               event type.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PhoneNumber" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The symbols and numerals required to contact
               an individual by telephone. The string may
               contain punctuation marks such as dash (-)
               or dot (.) to separate fields within the string.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PriorID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The resource identifier for a resource that
               is superseded or replaced by a resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProcessingLevel" type="enumProcessingLevel">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The standard classification of the processing
               performed on the product.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProductKey" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The key (identifier) of the resource within
               a Repository. This is a local identifier which
               can be used to retrieve or locate the resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProviderProcessingLevel" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The provider specific classification of the
               processing performed on the product.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProviderResourceName" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A short textual description of a resource
               used by the provider which may be used to
               identify a resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProviderVersion" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Describes the release or edition of the product
               used by the provider. The formation rule may
               vary between providers. It is intended to
               aid in queries to the provider regarding the
               product.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Qualifier" type="enumQualifier">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Characterizes the refinement to apply to a
               type or attribute of a quantity.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Quantity" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A value that describes a characteristic of
               a system.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="RelativeStopDate" type="xsd:duration" substitutionGroup="StopDateEntity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               An indication of the nominal end date relative
               to the present.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ReleaseDate" type="xsd:dateTime">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The date and time when a resource is made
               available. The availability of a resource
               coincides with the release of a resource description.
               If the Release Date is specified as a future
               date then it indicates that resource should
               not be made available until that time. However,
               this is only advisory and in practice the
               Release Date should be the actual date the
               resource description was published.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="RenderingAxis" type="enumRenderingAxis">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A reference component of a plot or rendering
               of data. A plot typically is a 2-dimensional
               rendering with a horizontal and verticle axis.
               A third dimension can be introduced with a
               color coding of the rendered data.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="RepositoryID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The identifier of an Repository resource.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ResourceID" type="ResourceID"/>
   <xsd:simpleType name="ResourceID">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A Resource ID is a URI that has the form "scheme://authority/path"
            where "scheme" is "spase" for those resources
            administered through the SPASE framework,
            "authority" is the unique identifier for the
            resource provider registered within the SPASE
            framework and "path" is the unique identifier
            of the resource within the context of the
            "authority". The resource ID must be unique
            within the SPASE framework.
         </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string"/>
   </xsd:simpleType>
   <xsd:element name="ResourceName" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A short textual description of a resource
               which may be useful when read by a person.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Role" type="enumRole">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The assigned or assumed function or position
               of an individual.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ScaleMax" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The maximum value that the variable is expected
               to attain. Used, for example, by automated
               plotting software.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ScaleMin" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The minimum value that the variable is expected
               to attain. Used, for example, by automated
               plotting software.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ScaleType" type="enumScaleType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The scaling to apply to an axis. If this attribute
               is not present, linear scale should be assumed.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Set" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A collection of items for a particular purpose.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Size" type="typeSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The number of elements in each dimension of
               a multi-dimensional array. A scalar has a
               size of 1. A multi-dimensional vector will
               have a size for each dimension. Note that
               the number of elements in the size of an N-dimensional
               array conveys the array's dimensionality while
               the product of those numbers conveys the total
               number of elements in the array. When size
               is used to describe a tensor it is the number
               of elements in the tensor. As such it has
               a limited set of values. A tensor of rank
               1 has a size of 3, rank 2 a size of 9, rank
               3 a size of 27 and rank n a size of 3^n.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="SourceType" type="enumSourceType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the function or purpose
               of the source.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="SpectralRange" type="enumSpectralRange">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The general term used to describe wavelengths
               or frequencies within a given span of values
               for those quantities.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="StartDate" type="xsd:dateTime">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The specification of a starting point in time.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="StartLocation" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The initial position in space.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="StopDate" type="xsd:dateTime" substitutionGroup="StopDateEntity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The specification of a stopping point in time.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="StopLocation" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The final position in space.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="SupportQuantity" type="enumSupportQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the support information.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="URL" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Uniform Resource Locator (URL) is the global
               address of documents and other resources on
               the World Wide Web. The first part of the
               address indicates what protocol to use, and
               the second part specifies the IP address or
               the domain name where the resource is located
               followed by the pathname of the resource.
               A URL is specified in the form protocol://server.domain.name:port/pathname.
               Example protocols are HTTP or FTP, server
               domain name is the Internet name.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Units" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A description of the standardized measurement
               increments in which a value is specified.
               The description is represented as a mathematical
               phrase. Units should be represented by widely
               accepted representation. For example, units
               should conform to the International System
               of Units (SI) which is maintained by BIPM
               (Bureau International des Poids et Mesures
               (see &lt;http://www.bipm.fr/&gt; ) when appropriate
               or use tokens like "Re" to represent units
               of the Radius of the Earth. Within a phrase
               the circumflex (^) is used to indicate a power,
               a star (*) is used to indicate multiplication
               and a slash (/) division. When symbols are
               not separated by a mathematical operator,
               multiplication is assumed. Symbols for base
               units can be found at: &lt;http://www.bipm.fr/en/si/si_brochure/chapter2/2-1/#symbols&gt;
               and those for common derived units can be
               found at: &lt;http://www.bipm.fr/en/si/derived_units/2-2-2.html&gt;
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="UnitsConversion" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The multiplicative factor for converting a
               unit into International System of Units (SI)
               units. The factor is expressed in the form
               "number &gt; x", where "number" is a numerical
               value and "x" is the appropriate SI units.
               The basic SI units are Enumerated: m (meter),
               N (newton), kg (kilogram), Pa (pascal), s
               (second), Hz (hertz), A (ampere), V (volt),
               K (kelvin), W (watt), rad (radian), J (joule),
               sr (steradian), C (coulomb), T (tesla), ohm
               (ohm), mho (mho or seimens), H (henry), and
               F (farad). Two useful units which are not
               SI units are: degree (angle), and unitless
               (no units). An example is: "1.0E-9&gt;T" which
               converts the units, presumable nT, to Tesla.
               Another example is: "1.0e+3&gt;m/s" which converts
               a velocity expressed in kilometers per second
               to meters per second.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ValidMax" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The largest legitimate value.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ValidMin" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               The smallest legitimate value.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ValueFormat" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A string defining the output format used when
               extracting data values out to a file or screen.
               The magnitude and the number of significant
               figures needed should be carefully considered.
               The output format string can be in either
               Fortran or C syntax.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Version" type="enumVersion">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Indicates the release identifier. When used
               to indicate the release of the SPASE data
               model, it is a in the form Major.Minor.Fix
               where Major: A significant change in the architecture
               of the model or rewrite of the implementation.
               This includes major changes in design or implementation
               language. This number starts at 0 (zero).
               Minor: An addition of terms or features that
               require changes in documentation/external
               API. This number starts at 0 (zero). Fix:
               Any change that doesn't require documentation/external
               API changes. This number starts at 0 (zero).
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="WaveQuantity" type="enumWaveQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the physical properties
               of a wave.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="WaveType" type="enumWaveType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the carrier or phenomenon
               of wave information observed by the measurement.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <!-- ================================
      Lists
     ================================ -->
   <!-- ==========================
Version
========================== -->
   <xsd:simpleType name="enumVersion">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Version number.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="2.2.2"/>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Access Rights

Identifiers for permissions granted or denied
by the host of a product to allow other users
to access and use the resource.
========================== -->
   <xsd:simpleType name="enumAccessRights">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for permissions granted or denied
               by the host of a product to allow other users
               to access and use the resource.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Open">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Access is granted to everyone.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Restricted">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Access to the product is regulated and requires
            some form of identification.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Annotation Type

Identifiers for an classification of an annotation.
========================== -->
   <xsd:simpleType name="enumAnnotationType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for an classification of an annotation.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Anomaly">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An interval where measurements or observations
            may be adversely affected.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Event">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An action or observation which occurs at a
            point in time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Feature">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A prominent or distinctive characteristic
            that occurs at a location or persists over
            a period of time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Association Type

Identifiers for resource associations.
========================== -->
   <xsd:simpleType name="enumAssociationType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for resource associations.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ChildEventOf">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A descendant or caused by another resource.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DerivedFrom">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A transformed or altered version of a resource
            instance.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ObservedBy">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Detected or originating from another resource.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Other">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Not classified with more specific terms. The
            context of its usage may be described in related
            text.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PartOf">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A portion of a larger resource.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="RevisionOf">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A modified version of a resource instance.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Availability

Identifiers for indicating the method or service
which may be used to access the resource.
========================== -->
   <xsd:simpleType name="enumAvailability">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for indicating the method or service
               which may be used to access the resource.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Offline">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Not directly accessible electronically. This
            includes resources which may to be moved to
            an on-line status in response to a given request.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Online">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Directly accessible electronically.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Classification Method

Identifiers for the technique used to determine
the characteristics of an object.
========================== -->
   <xsd:simpleType name="enumClassificationMethod">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the technique used to determine
               the characteristics of an object.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Automatic">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Determined by the analysis or assessment performed
            by a program or server.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Inferred">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Determined by the analysis of other information
            or resources.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Inspection">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Determined by the analysis or assessment performed
            by a person.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Component

Identifiers for the axis of coordinate systems.
========================== -->
   <xsd:simpleType name="enumComponent">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the axis of coordinate systems.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="I">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Projection of a vector along the first named
            axis of a coordinate system. Typically the
            X axis, but could be the R axis for an RTN
            coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="J">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Projection of a vector along the second named
            axis of a coordinate system. Typically the
            Y axis, but could be the T axis for an RTN
            coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="K">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Projection of a vector along the third named
            axis of a coordinate system. Typically the
            Z axis, but could be the N axis for an RTN
            coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Confidence Rating

Identifiers for the classification of the
certainty of an assertion.
========================== -->
   <xsd:simpleType name="enumConfidenceRating">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the classification of the
               certainty of an assertion.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Probable">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Likely given the available evidence. Considered
            in the range of 4-7 on a scale of 0-10.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Strong">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Highly likely given the available evidence.
            Considered in the range of 7-10 on a scale
            of 0-10.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Unlikely">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Not likely given the available evidence. Considered
            in the range of 0 on a scale of 0-10.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Weak">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Slightly likely given the available evidence.
            Considered in the range of 1-4 on a scale
            of 0-10.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Coordinate Representation

Identifiers of the method or form for specifying
a given point or vector in a given coordinate
system.
========================== -->
   <xsd:simpleType name="enumCoordinateRepresentation">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers of the method or form for specifying
               a given point or vector in a given coordinate
               system.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Cartesian">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A representation in which a position vector
            or a measured vector (e.g., field or flow)
            is specified by its components along the base
            axes of the coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Cylindrical">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A coordinate representation of a position
            vector or measured vector (field or flow)
            by its k-component, the magnitude of its projection
            into the i-j plane, and the azimuthal angle
            of the i-j plane projection.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Spherical">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A coordinate representation of a position
            vector or of a measured vector by its magnitude
            and two direction angles. The angles are relative
            to the base axes of the coordinate system
            used. Typically the angles are phi [azimuth
            angle, =arctan (j/i)] and theta, where theta
            may be a polar angle, arctan {[SQRT(i^2+j^2)]/k},
            or an elevation angle, arctan [k/SQRT (i^2+j^2)].
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Coordinate System Name

Identifiers of the origin and orientation
of a set of typically orthogonal axes.
========================== -->
   <xsd:simpleType name="enumCoordinateSystemName">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers of the origin and orientation
               of a set of typically orthogonal axes.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="CGM">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Corrected Geomagnetic - A coordinate system
            from a spatial point with GEO radial distance
            and geomagnetic latitude and longitude, follow
            the epoch-appropriate IGRF/DGRF model field
            vector through to the point where the field
            line crosses the geomagnetic dipole equatorial
            plane. Then trace the dipole magnetic field
            vector Earthward from that point on the equatorial
            plane, in the same hemisphere as the original
            point, until the initial radial distance is
            reached. Designate the dipole latitude and
            longitude at that point as the CGM latitude
            and longitude of the original point. See &lt;http://nssdc.gsfc.nasa.gov/space/cgm/cgmm_des.html&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Carrington">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A coordinate system which is centered at the
            Sun and is "fixed" with respect to the synodic
            rotation rate; the mean synodic value is about
            27.2753 days. The Astronomical Almanac gives
            a value for Carrington longitude of 349.03
            degrees at 0000 UT on 1 January 1995.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DM">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Dipole Meridian - A coordinate system centered
            at the observation point. Z axis is parallel
            to the Earth's dipole axis, positive northward.
            X is in the plane defined by Z and the line
            linking the observation point with the Earth's
            center. Y is positive eastward. See &lt;http://cdpp.cnes.fr/00428.pdf&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GEI">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Geocentric Equatorial Inertial - A coordinate
            system where the Z axis is along Earth's spin
            vector, positive northward. X axis points
            towards the first point of Aries (from the
            Earth towards the Sun at the vernal equinox).
            See Russell, 1971
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GEO">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Geographic - geocentric corotating - A coordinate
            system where the Z axis is along Earth's spin
            vector, positive northward. X axis lies in
            Greenwich meridian, positive towards Greenwich.
            See Russell, 1971.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GPHIO">
            <xsd:annotation>
               <xsd:documentation>In this Cartesian coordinate system, X
                  is along the flow direction, Y is along the Ganymede–Jupiter
                  vector, and Z is along the spin axis. These coordinates are analogous
                  to the earth-centered GSE coordinates that relate to the
                  direction of flow of the solar wind onto Earth’s environment.</xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GSE">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Geocentric Solar Ecliptic - A coordinate system
            where the X axis is from Earth to Sun. Z axis
            is normal to the ecliptic, positive northward.
            See Russell, 1971.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GSEQ">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Geocentric Solar Equatorial - A coordinate
            system where the X axis is from Earth to Sun.
            Y axis is parallel to solar equatorial plane.
            Z axis is positive northward. See Russell,
            1971
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GSM">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Geocentric Solar Magnetospheric - A coordinate
            system where the X axis is from Earth to Sun,
            Z axis is northward in a plane containing
            the X axis and the geomagnetic dipole axis.
            See Russell, 1971
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HAE">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Heliocentric Aries Ecliptic - A coordinate
            system where the Z axis is normal to the ecliptic
            plane, positive northward. X axis is positive
            towards the first point of Aries (from Earth
            to Sun at vernal equinox). Same as SE below.
            See Hapgood, 1992.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HCC">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Heliocentric Cartesian - A 3-D orthonormal
            coordinate system that is primarily intended
            to specify with two dimensions a point on
            the solar disk. The Z axis points toward the
            observer. The Y axis lies in the plane defined
            by the solar spin vector and the Z axis, positive
            northward. The X axis is perpendicular to
            the Y and Z axes, positive toward solar west.
            Standard representation for this system is
            via the point's x and y values, expressed
            either as physical distances or as fractions
            of the solar disk radius.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HCI">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Heliographic Carrington Inertial.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HCR">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Heliocentric Radial - A 3-D orthonormal coordinate
            system that is primarily intended to specify
            with two dimensions a point on the solar disk.
            The Z axis points toward the observer. The
            Y axis lies in the plane defined by the solar
            spin vector and the Z axis, positive northward.
            The X axis is perpendicular to the Y and Z
            axes, positive toward solar west. Standard
            representation for this system is via the
            point's distance rho from the Z axis [Rho
            = SQRT(x**2 + y**2)] and its phase angle psi
            measured counterclockwise from the +Y axis
            [psi = arctan (-y/x)]
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HEE">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Heliocentric Earth Ecliptic - A coordinate
            system where the Z axis is normal to the ecliptic
            plane, positive northward. X axis points from
            Sun to Earth. See Hapgood, 1992
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HEEQ">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Heliocentric Earth Equatorial - A coordinate
            system where the Z axis is normal to the solar
            equatorial plane, positive northward. X axis
            is generally Earthward in the plane defined
            by the Z axis and the Sun-Earth direction.
            See Hapgood, 1992.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HG">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Heliographic - A heliocentric rotating coordinate
            system where the Z axis is normal to the solar
            equatorial plane, positive northward. X, Y
            axes rotate with a 25.38 day period. The zero
            longitude (X axis) is defined as the longitude
            that passed through the ascending node of
            the solar equator on the ecliptic plane on
            1 January, 1854 at 12 UT. See &lt;http://nssdc.gsfc.nasa.gov/space/helios/coor_des.html&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HGI">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Heliographic Inertial - A heliocentric coordinate
            system where the Z axis is normal to the solar
            equatorial plane, positive northward. X axis
            is along the intersection line between solar
            equatorial and ecliptic planes. The X axis
            was positive at SE longitude of 74.367 deg
            on Jan 1, 1900. (See SE below.) See &lt;http://nssdc.gsfc.nasa.gov/space/helios/coor_des.html&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HPC">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Helioprojective Cartesian = A 3-D orthonormal
            (left-handed) coordinate system that is primarily
            intended to specify with two dimensions a
            point on the solar disk. The Z axis points
            from the observer to the center of the solar
            disk. The Y axis lies in the plane defined
            by the solar spin vector and the Z axis, positive
            northward. The X axis is perpendicular to
            the Y and Z axes, positive toward solar west.
            Given as the distance between the observer
            and the center of the solar disk, the standard
            representation of an (x,y) point on the solar
            disk is via the point's longitude angle [arctan
            (x/d)] and latitude angle [arctan y/d].
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HPR">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Helioprojective Radial - A 3-D orthonormal
            (left-handed) coordinate system that is primarily
            intended to specify with two dimensions a
            point on the solar disk. The Z axis points
            from the observer to the center of the solar
            disk. The Y axis lies in the plane defined
            by the solar spin vector and the Z axis, positive
            northward. The X axis is perpendicular to
            the Y and Z axes, positive toward solar west.
            Given as the distance between the observer
            and the center of the solar disk, the standard
            representation for this system of an (x,y)
            point on the solar disk is via the point's
            latitude angle theta {= arctan [SQRT(x**2
            + y**2)]/d]} or equivalent declination parameter
            delta (= theta - 90 deg), and its phase angle
            psi as measured counter- clockwise from the
            +Y axis [psi = arctan (-y/x)].
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="J2000">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An astronomical coordinate system which uses
            the mean equator and equinox of Julian date
            2451545.0 TT (Terrestrial Time), or January
            1, 2000, noon TT. (aka J2000) to define a
            celestial reference frame.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="JSM">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
                  Jovian Solar Magnetospheric - A coordinate
                  system where the X axis is from Jupiter to Sun,
                  Z axis is northward in a plane containing
                  the X axis and the Jovian dipole axis.
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="JSO">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
                  Coordinate Sytem Related to Jupiter
                  Jovian Solar Orbital (X anti-sunward, Y along the orbital velocity direction)
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="KSM">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
                  Kronian Solar Magnetospheric - A coordinate
                  system where the X axis is from Saturn to Sun,
                  Z axis is northward in a plane containing
                  the X axis and the Kronian dipole axis.
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="KSO">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
                  Coordinate Sytem Related to Saturn
                  Kronian Solar Orbital (X anti-sunward, Y along the orbital velocity direction)
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="LGM">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Local Geomagnetic - A coordinate system used
            mainly for Earth surface or near Earth surface
            magnetic field data. X axis northward from
            observation point in a geographic meridian.
            Z axis downward towards Earth's center. In
            this system, H (total horizontal component)
            = SQRT (Bx^2 + By^2) and D (declination angle)
            = arctan (By/Bx)
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MAG">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Geomagnetic - geocentric. Z axis is parallel
            to the geomagnetic dipole axis, positive north.
            X is in the plane defined by the Z axis and
            the Earth's rotation axis. If N is a unit
            vector from the Earth's center to the north
            geographic pole, the signs of the X and Y
            axes are given by Y = N x Z, X = Y x Z.. See
            Russell, 1971, and &lt;http://cdpp.cnes.fr/00428.pdf&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MFA">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Magnetic Field Aligned - A coordinate system
            spacecraft-centered system with Z in the direction
            of the ambient magnetic field vector. X is
            in the plane defined by Z and the spacecraft-Sun
            line, positive sunward. See &lt;http://cdpp.cnes.fr/00428.pdf&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MSO">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
                  Coordinate Sytem Related to Mars or Mercury
                  Depending on the Targeted Region
                  Mars/Mercury Solar Orbital (X anti-sunward, Y along the orbital velocity direction)
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="RTN">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Radial Tangential Normal. Typically centered
            at a spacecraft. Used for IMF and plasma V
            vectors. R (radial) axis is radially away
            from the Sun, T (tangential) axis is normal
            to the plane formed by R and the Sun's spin
            vector, positive in the direction of planetary
            motion. N (normal) is R x T.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SC">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Spacecraft - A coordinate system defined by
            the spacecraft geometry and/or spin. Often
            has Z axis parallel to spacecraft spin vector.
            X and Y axes may or may not corotate with
            the spacecraft. See SR and SR2 below.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SE">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Solar Ecliptic - A heliocentric coordinate
            system where the Z axis is normal to the ecliptic
            plane, positive northward. X axis is positive
            towards the first point of Aries (from Earth
            to Sun at vernal equinox). Same as HAE above.
            See &lt;http://nssdc.gsfc.nasa.gov/space/helios/coor_des.html&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SM">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Solar Magnetic - A geocentric coordinate system
            where the Z axis is northward along Earth's
            dipole axis, X axis is in plane of z axis
            and Earth-Sun line, positive sunward. See
            Russell, 1971.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SR">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Spin Reference - A special case of a Spacecraft
            (SC) coordinate system for a spinning spacecraft.
            Z is parallel to the spacecraft spin vector.
            X and Y rotate with the spacecraft. See &lt;http://cdpp.cnes.fr/00428.pdf&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SR2">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Spin Reference 2 - A special case of a Spacecraft
            (SC) coordinate system for a spinning spacecraft.
            Z is parallel to the spacecraft spin vector.
            X is in the plane defined by Z and the spacecraft-Sun
            line, positive sunward. See &lt;http://cdpp.cnes.fr/00428.pdf&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SSE">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Spacecraft Solar Ecliptic - A coordinate system
            used for deep space spacecraft, for example
            Helios. - X axis from spacecraft to Sun. Z
            axis normal to ecliptic plane, positive northward.
            Note: Angle between normals to ecliptic and
            to Helios orbit plane ~ 0.25 deg.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SSE_L">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Selenocentric Solar Ecliptic.  The X axis
            points from the center of the Earth's moon
            to the sun, the Z axis is normal to the ecliptic
            plane, positive northward.  And the Y axis
            completes the right-handed set of axes.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SpacecraftOrbitPlane">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A coordinate system where X lies in the plane
            normal to and in the direction of motion of
            the spacecraft, Z is normal to this plane
            and Y completes the triad in a right-handed
            coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="VSO">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
                  Coordinate Sytem Related to Venus
                  Venus Solar Orbital (X anti-sunward, Y along the orbital velocity direction)
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="WGS84">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The World Geodetic System (WGS) defines a
            reference frame for the earth, for use in
            geodesy and navigation. The WGS84 uses the
            zero meridian as defined by the Bureau International
            de l'Heure.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         
         
         
         
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Direction Angle

Identifiers for the angle between a vector
and a base axis.
========================== -->
   <xsd:simpleType name="enumDirectionAngle">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the angle between a vector
               and a base axis.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="AzimuthAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The angle between the projection into the
            i-j plane of a position or measured vector
            and the i-axis of the coordinate system. Mathematically
            defined as arctan(j/i).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ElevationAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The angle between the position or measured
            vector and the i-j plane of the coordinate
            system. Mathematically defined as arctan(k/SQRT(i^2+j^2)).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PolarAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The angle between the position or measured
            vector and the k-axis of the coordinate system.
            Mathematically defined as arctan([SQRT(i^2+j^2)]/k).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Display Type

Identifiers for types or classes of rendered
data.
========================== -->
   <xsd:simpleType name="enumDisplayType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for types or classes of rendered
               data.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Image">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A two-dimensional representation of data with
            values at each element of the array related
            to an intensity or a color.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Plasmagram">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The characterization of signal strengths in
            active sounding measurements as a function
            of virtual range or signal delay time and
            sounding frequency. A Plasmagram is also referred
            to as an Ionogram.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Spectrogram">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The characterization of signal strengths as
            a function of frequency (or energy) and time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="StackPlot">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A representation of data showing multiple
            sets of observations on a single plot, possibly
            offsetting each plot by some uniform amount.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TimeSeries">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A representation of data showing a set of
            observations taken at different points in
            time and charted as a time series.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="WaveForm">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Spatial or temporal variations of wave amplitude
            over wave-period timescales.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Document Type

Identifiers for the characterization of the
content or purpose of a document.
========================== -->
   <xsd:simpleType name="enumDocumentType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the characterization of the
               content or purpose of a document.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Other">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Poster">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A set of information arranged on a single
            page or sheet, typically in a large format.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Presentation">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A set of information that is used when communicating
            to an audience.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Report">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A document which describes the findings of
            some individual or group.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Specification">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A detailed description of the requirements
            and other aspects of an object or component
            that may be used to develop an implementation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TechnicalNote">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A document summarizing the performance and
            other technical characteristics of a product,
            machine, component, subsystem or software
            in sufficient detail to be used by an engineer
            or researcher.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="WhitePaper">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An authoritative report giving information
            or proposals on an issue.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Earth

Identifiers for the regions surrounding the
Earth.
========================== -->
   <xsd:simpleType name="enumEarth">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the regions surrounding the
               Earth.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Magnetosheath">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region between the bow shock and the magnetopause,
            characterized by very turbulent plasma.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnetosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of space above the atmosphere or
            surface of the planet, and bounded by the
            magnetopause, that is under the direct influence
            of the planet's magnetic field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnetosphere.Magnetotail">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region on the night side of the body where
            the magnetic filed is stretched backwards
            by the force of the solar wind. For Earth,
            the magnetotail begins at a night-side radial
            distance of 10 Re (X &gt; -10Re).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnetosphere.Main">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the magnetosphere where the
            magnetic field lines are closed, but does
            not include the gaseous region gravitationally
            bound to the body.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnetosphere.Polar">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region near the pole of a body. For a
            magnetosphere the polar region is the area
            where magnetic field lines are open and includes
            the auroral zone.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnetosphere.RadiationBelt">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region within a magnetosphere where high-energy
            particles could potentially be trapped in
            a magnetic field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The gaseous and possibly ionized environment
            of a body extending from the surface to some
            specified altitude. For the Earth, this altitude
            is 2000 km.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Atmosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The neutral gases surrounding a body that
            extends from the surface and is bound to the
            body by virtue of the gravitational attraction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.AuroralRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region in the atmospheric where electrically-charged
            particles bombarding the upper atmosphere
            of a planet in the presence of a magnetic
            field produce an optical phenomenon.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.EquatorialRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region centered on the equator and limited
            in latitude by approximately 23 degrees north
            and south of the equator.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Ionosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The charged or ionized gases surrounding a
            body that are nominally bound to the body
            by virtue of the gravitational attraction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Ionosphere.DRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the ionosphere that exists approximately
            50 to 95 km above the surface of the Earth.
            One of several layers in the ionosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Ionosphere.ERegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A layer of ionised gas occurring at 90-150km
            above the ground. One of several layers in
            the ionosphere. Also called the The Kennelly-Heaviside
            layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Ionosphere.FRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A layer that contains ionized gases at a height
            of around 150-800 km above sea level, placing
            it in the thermosphere. the F region has the
            highest concentration of free electrons and
            ions anywhere in the atmosphere. It may be
            thought of as comprising two layers, the F1-and
            F2-layers. One of several layers in the ionosphere.
            Also known as the Appleton layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Ionosphere.Topside">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region at the upper most areas of the
            ionosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Mesosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the Stratosphere to a range of 80 km to 85
            km, temperature decreasing with height.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Plasmasphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region of the magnetosphere consisting of
            low energy (cool) plasma. It is located above
            the ionosphere. The outer boundary of the
            plasmasphere is known as the plasmapause,
            which is defined by an order of magnitude
            drop in plasma density.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.PolarCap">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The areas of the globe surrounding the poles
            and consisting of the region north of 60 degrees
            north latitude an the region south of 60 degrees
            south latitude.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.SouthAtlanticAnomalyRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region where the Earth's inner van Allen
            radiation belt makes its closest approach
            to the planet's surface. The result is that,
            for a given altitude, the radiation intensity
            is higher over this region than elsewhere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Stratosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the troposphere to about 30 km, temperature
            increases with height. The stratosphere contains
            the ozone layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Thermosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the Mesosphere to 640+ km, temperature increasing
            with height.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearSurface.Troposphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The lowest layer of the atmosphere which begins
            at the surface and extends to between 7 km
            (4.4 mi) at the poles and 17 km (10.6 mi)
            at the equator, with some variation due to
            weather factors.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Surface">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The outermost area of a solid object.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Encoding

Identifiers for unambiguous rules that establishes
the representation of information within a
file.
========================== -->
   <xsd:simpleType name="enumEncoding">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for unambiguous rules that establishes
               the representation of information within a
               file.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ASCII">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sequence of characters that adheres to American
            Standard Code for Information Interchange
            (ASCII) which is an 7-bit character-coding
            scheme.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="BZIP2">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An open standard algorithm by Julian Seward
            using Burrows-Wheeler block sorting and Huffman
            coding. See &lt;http://www.bzip.org/&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Base64">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A data encoding scheme whereby binary-encoded
            data is converted to printable ASCII characters.
            It is defined as a MIME content transfer encoding
            for use in Internet e-mail. The only characters
            used are the upper- and lower-case Roman alphabet
            characters (A-Z, a-z), the numerals (0-9),
            and the "+" and "/" symbols, with the "="
            symbol as a special suffix (padding) code.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GZIP">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An open standard algorithm distributed by
            GHU based on LZ77 and Huffman coding. See
            &lt;http://www.gnu.org/software/gzip/gzip.html&gt;
            or &lt;http://www.gzip.org/&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="None">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A lack or absence of anything.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="S3_BUCKET">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A container of objects that comply with the
            Amazon Simple Storage Service (S3) specifications.
            A bucket has a unique, user-assigned key (name).
            A bucket can contain any number of objects
            with an aggregate size of 5 gigabytes. A bucket
            may be accompanied by up to 2 kilobytes of
            metadata.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TAR">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A file format used to collate collections
            of files into one larger file, for distribution
            or archiving, while preserving file system
            information such as user and group permissions,
            dates, and directory structures. The format
            was standardized by POSIX.1-1988 and later
            POSIX.1-2001.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Unicode">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Text in multi-byte Unicode format.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ZIP">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An open standard for compression which is
            a variation of the LZW method and was originally
            used in the PKZIP utility.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Field Quantity

Identifiers for the physical attribute of
the field.
========================== -->
   <xsd:simpleType name="enumFieldQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the physical attribute of
               the field.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Current">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The flow of electrons through a conductor
            caused by a potential difference.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Electric">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The physical attribute that exerts an electrical
            force.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Electromagnetic">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Electric and magnetic field variations in
            time and space that propagate through a medium
            or a vacuum with the wave's propagation, electric
            field, and magnetic field vectors forming
            an orthogonal triad. Waves in this category
            are detected by having their field quantities
            measured.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Gyrofrequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of gyrations around a magnetic
            guiding center (field line) a charged particle
            makes per unit time due to the Lorentz force.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnetic">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The physical attribute attributed to a magnet
            or its equivalent.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PlasmaFrequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A number-density-dependent characteristic
            frequency of a plasma.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Potential">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A field which obeys Laplace's Equation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PoyntingFlux">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Electromagnetic energy flux transported by
            a wave characterized as the rate of energy
            transport per unit area per steradian.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Format

Identifiers for data organized according to
preset specifications.
========================== -->
   <xsd:simpleType name="enumFormat">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for data organized according to
               preset specifications.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="AVI">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Audio Video Interleave (AVI) a digital format
            for movies that conforms to the Microsoft
            Windows Resource Interchange File Format (RIFF).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Binary">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A direct representation of the bits which
            may be stored in memory on a computer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CDF">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Common Data Format (CDF). A binary storage
            format developed at Goddard Space Flight Center
            (GSFC).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CEF">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Cluster Exchange Format (CEF) is a self-documenting
            ASCII format designed for the exchange of
            data. There are two versions of CEF which
            are not totally compatible.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CEF1">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Cluster Exchange Format (CEF), version 1,
            is a self-documenting ASCII format designed
            for the exchange of data. The metadata contains
            information compatible with the ISTP recommendations
            for CDF.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CEF2">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Cluster Exchange Format (CEF), version 2,
            is a self-documenting ASCII format designed
            for the exchange of data and introduced for
            Cluster Active Archive. Compared to version
            1, the metadata description of vectors and
            tensors is different.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Excel">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A Microsoft spreadsheet format used to hold
            a variety of data in tables which can include
            calculations.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FITS">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Flexible Image Transport System (FITS) is
            a digital format primarily designed to store
            scientific data sets consisting of multi-dimensional
            arrays (1-D spectra, 2-D images or 3-D data
            cubes) and 2-dimensional tables containing
            rows and columns of data.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GIF">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Graphic Interchange Format (GIF) first introduced
            in 1987 by CompuServe. GIF uses LZW compression
            and images are limited to 256 colours.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HDF">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Hierarchical Data Format
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HDF4">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Hierarchical Data Format, Version 4
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HDF5">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Hierarchical Data Format, Version 5
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HTML">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A text file containing structured information
            represented in the HyperText Mark-up Language
            (HTML). See &lt;http://www.w3.org/MarkUp/&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Hardcopy">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A permanent reproduction, or copy in the form
            of a physical object, of any media suitable
            for direct use by a person.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Hardcopy.Film">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An image recording medium on which usually
            a "negative" analog image is registered. A
            "positive" image can be recovered or reproduced
            from film, which is usually made of flexible
            materials for ease of storage and transportation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Hardcopy.Microfiche">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sheet of microfilm on which many pages of
            material have been photographed; a magnification
            system is used to read the material.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Hardcopy.Microfilm">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Film rolls on which materials are photographed
            at greatly reduced size; a magnification system
            is used to read the material.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Hardcopy.Photograph">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An image (positive or negative) registered
            on a piece of photo-sensitive paper
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Hardcopy.PhotographicPlate">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A rigid (typically glass) medium that functions
            like film. Its rigidity is for guarding against
            image distortion due to medium deformation
            (caused by heat and humidity). Photographic
            plates are often used for astronomical photography.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Hardcopy.Print">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sheet of any written or printed material
            which may include notes or graphics. Multiple
            printed pages may be bound into a manuscript
            or book.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="IDFS">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Instrument Data File Set (IDFS) is a set of
            files written in a prescribed format which
            contain data, timing data, and meta-data.
            IDFS was developed at Southwest Research Institute
            (SwRI).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="IDL">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Interactive Data Language (IDL) save set.
            IDL is a proprietary format.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="JPEG">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A binary format for still images defined by
            the Joint Photographic Experts Group
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MATLAB_4">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            MATLAB Workspace save set, version 4. MAT-files
            are double-precision, binary, MATLAB format
            files. MATLAB is a proprietary product of
            The MathWorks.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MATLAB_6">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            MATLAB Workspace save set, version 6. MAT-files
            are double-precision, binary, MATLAB format
            files. MATLAB is a proprietary product of
            The MathWorks.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MATLAB_7">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            MATLAB Workspace save set, version 7. MAT-files
            are double-precision, binary, MATLAB format
            files. Version 7 includes data compression
            and Unicode encoding. MATLAB is a proprietary
            product of The MathWorks.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MPEG">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A digital format for movies defined by the
            Motion Picture Experts Group
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NCAR">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The National Center for Atmospheric Research
            (NCAR) format. A complete description of that
            standard is given in appendix C of the "Report
            on Establishment &amp; Operation of the Incoherent-
            Scatter Data Base", dated August 23, 1984,
            obtainable from NCAR, P.O. Box 3000 Boulder,
            Colorado 80307-3000.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NetCDF">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Unidata Program Center's Network Common Data
            Form (NetCDF). A self-describing portable
            data format for array-oriented data access.
            See &lt;http://my.unidata.ucar.edu/content/software/netcdf&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PDF">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A document expressed in the Portable Document
            Format (PDF) as defined by Adobe.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PNG">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A digital format for still images. Portable
            Network Graphics (PNG)
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Postscript">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A page description programming language created
            by Adobe Systems Inc. that is a device-independent
            industry standard for representing text and
            graphics.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="QuickTime">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A format for digital movies, as defined by
            Apple Computer. See &lt;http://developer.apple.com/quicktime/&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TIFF">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A binary format for still pictures. Tagged
            Image Format File (TIFF). Originally developed
            by Aldus and now controlled by Adobe.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Text">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sequence of characters which may have an
            imposed structure or organization.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Text.ASCII">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sequence of characters that adheres to American
            Standard Code for Information Interchange
            (ASCII) which is an 7-bit character-coding
            scheme.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Text.Unicode">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Text in multi-byte Unicode format.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="UDF">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Universal Data Format (UDF). The Optical Technology
            Storage Association's Universal Disk Format,
            based on ISO 13346. See &lt;http://www.osta.org/specs/index.htm&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="VOTable">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A proposed IVOA standard designed as a flexible
            storage and exchange format for tabular data.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="XML">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            eXtensible Mark-up Language (XML). A structured
            format for representing information. See &lt;http://www.w3.org/XML/&gt;
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Hardcopy

Identifiers for permanent reproductions, or
copy in the form of a physical object, of
any media suitable for direct use by a person.
========================== -->
   <xsd:simpleType name="enumHardcopy">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for permanent reproductions, or
               copy in the form of a physical object, of
               any media suitable for direct use by a person.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Film">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An image recording medium on which usually
            a "negative" analog image is registered. A
            "positive" image can be recovered or reproduced
            from film, which is usually made of flexible
            materials for ease of storage and transportation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Microfiche">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sheet of microfilm on which many pages of
            material have been photographed; a magnification
            system is used to read the material.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Microfilm">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Film rolls on which materials are photographed
            at greatly reduced size; a magnification system
            is used to read the material.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Photograph">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An image (positive or negative) registered
            on a piece of photo-sensitive paper
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PhotographicPlate">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A rigid (typically glass) medium that functions
            like film. Its rigidity is for guarding against
            image distortion due to medium deformation
            (caused by heat and humidity). Photographic
            plates are often used for astronomical photography.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Print">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sheet of any written or printed material
            which may include notes or graphics. Multiple
            printed pages may be bound into a manuscript
            or book.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Hash Function

Identifiers for functions or algorithms that
convert a digital data object into a hash
value.
========================== -->
   <xsd:simpleType name="enumHashFunction">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for functions or algorithms that
               convert a digital data object into a hash
               value.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="MD5">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Message Digest 5 (MD5) is a 128-bit message
            digest algorithm created in 1991 by Professor
            Ronald Rivest.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SHA1">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Secure Hash Algorithm (SHA), a 160-bit message
            digest algorithm developed by the NSA and
            described in Federal Information Processing
            Standard (FIPS) publication 180-1.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SHA256">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Secure Hash Algorithm (SHA), a 256-bit message
            digest algorithm developed by the NSA and
            described in Federal Information Processing
            Standard (FIPS) publication 180-1.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Heliosphere

Identifiers for regions of the solar atmosphere
which extends roughly from the inner corona
to the edge of the solar plasma at the heliopause
separating primarily solar plasma from interstellar
plasma.
========================== -->
   <xsd:simpleType name="enumHeliosphere">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for regions of the solar atmosphere
               which extends roughly from the inner corona
               to the edge of the solar plasma at the heliopause
               separating primarily solar plasma from interstellar
               plasma.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Heliosheath">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region extending radially outward from
            the heliospheric termination shock and in
            which the decelerated solar wind plasma is
            still significant.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Inner">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the heliosphere extending radially
            outward from the solar coronal base to just
            inside 1 AU.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NearEarth">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The heliospheric region near the Earth which
            extends to and includes the area near the
            L1 and L2 Lagrange point.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Outer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the heliosphere extending radially
            outward from just outside 1 AU to the heliospheric
            termination shock.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Remote1AU">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A roughly toroidal region that includes the
            Earth's orbit, but exclusive of the region
            near the Earth.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Instrument Type

Identifiers for the type of experiment the
instrument performs. This is the technique
of observation.
========================== -->
   <xsd:simpleType name="enumInstrumentType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the type of experiment the
               instrument performs. This is the technique
               of observation.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Antenna">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sensor used to measure electric potential.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Channeltron">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument that detects electrons, ions,
            and UV-radiation, according to the principle
            of a secondary emission multiplier. It is
            typically used in electron spectroscopy and
            mass spectrometry.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Coronograph">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which can image things very
            close to the Sun by using a disk to block
            the Sun's bright surface which reveals the
            faint solar corona and other celestial objects.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DoubleSphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A dipole antenna of which the active (sensor)
            elements are small spheres located at the
            ends of two wires deployed in the equatorial
            plane, on opposite sides of a spinning spacecraft.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DustDetector">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which determines the mass and
            speed of ambient dust particles.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ElectronDriftInstrument">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An active experiment to measure the electron
            drift velocity based on sensing the displacement
            of a weak beam of electrons after one gyration
            in the ambient magnetic field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ElectrostaticAnalyser">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which uses charged plates to
            analyze the mass, charge and kinetic energies
            of charged particles which enter the instrument.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EnergeticParticleInstrument">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument that measures fluxes of charged
            particles as a function of time, direction
            of motion, mass, charge and/or species.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FaradayCup">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument consisting of an electrode from
            which electrical current is measured while
            a charged particle beam (electrons or ions)
            impinges on it. Used to determine energy spectrum
            and sometimes ion composition of the impinging
            particles.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FluxFeedback">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A search coil whose bandwidth and signal/noise
            ratio are increased by the application of
            negative feedback at the sensor (flux) level
            by driving a collocated coil with a signal
            from the preamplifier.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FourierTransformSpectrograph">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument that determines the spectra
            of a radiative source, using time-domain measurements
            and a Fourier transform.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GeigerMuellerTube">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures density of ionizing
            radiation based on interactions with a gas.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Imager">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which samples the radiation
            from an area at one or more spectral ranges
            emitted or reflected by an object.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ImagingSpectrometer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which is a multispectral scanner
            with a very large number of channels (64-256
            channels) with very narrow band widths.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Interferometer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument to study the properties of two
            or more waves from the pattern of interference
            created by their superposition.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="IonChamber">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A device in which the collected electrical
            charge from ionization in a gas-filled cavity
            is taken to be the proportion to some parameter
            (e.g. dose or exposure) of radiation field
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="IonDrift">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A device which measures the current produced
            by the displacement of ambient ions on a grid,
            thereby allowing the determination of the
            ion trajectory and velocity.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="LangmuirProbe">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A monopole antenna associated with an instrument.
            The instrument applies a potential to the
            antenna which is swept to determine the voltage/current
            characteristic. This provides information
            about the plasma surrounding the probe and
            spacecraft.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="LongWire">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A dipole antenna whose active (sensor) elements
            are two wires deployed in the equatorial plane
            on opposite sides of a spinning spacecraft,
            and whose length is several times greater
            than the spacecraft diameter.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnetometer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures the ambient magnetic
            field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MassSpectrometer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which distinguishes chemical
            species in terms of their different isotopic
            masses.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MicrochannelPlate">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument used for the detection of elementary
            particles, ions, ultraviolet rays and soft
            X-rays constructed from very thin conductive
            glass capillaries.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MultispectralImager">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which captures images at multiple
            spectral ranges.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NeutralAtomImager">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures the quantity
            and properties of neutral particles over a
            range of angles. Measured properties can include
            mass and energy.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NeutralParticleDetector">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures the quantity
            and properties of neutral particles. Measured
            properties can include mass and plasma bulk
            densities.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ParticleCorrelator">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which correlates particle flux
            to help identify wave/particle interactions.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ParticleDetector">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which detects particle flux!!!
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Photometer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures the strength
            of electromagnetic radiation within a spectral
            band which can range from ultraviolet to infrared
            and includes the visible spectrum.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Photopolarimeter">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures the intensity
            and polarization or radiant energy. A photopolarimeter
            is a combination of a photometer and a polarimeter.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Platform">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A collection of components which can be positioned
            and oriented as a single unit. A platform
            may contain other platforms. For example,
            a spacecraft is a platform which may have
            components that can be articulated and are
            also considered platforms.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ProportionalCounter">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures energy of ionization
            radiation based on interactions with a gas.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="QuadrisphericalAnalyser">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument used for the 3-D detection of
            plasma, energetic electrons and ions, and
            for positive-ion composition measurements.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Radar">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument that uses directional properties
            of returned power to infer spatial and/or
            other characteristics of a remote object.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Radiometer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument for detecting or measuring radiant
            energy. Radiometers are commonly limited to
            infrared radiation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ResonanceSounder">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A combination of a radio receiver and a pulsed
            transmitter used to study the plasma surrounding
            a spacecraft by identifying resonances or
            cut-offs (of the wave dispersion relation),
            whose frequencies are related to the ambient
            plasma density and magnetic field. When the
            transmitter is off it is essentially a high
            frequency-resolution spectral power receiver.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="RetardingPotentialAnalyser">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures ion temperatures
            and ion concentrations using a planar ion
            trap.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Riometer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measure the signal strength
            in various directions of the galactic radio
            signals. Variations in these signals are influenced
            by solar flare activity and geomagnetic storm
            and substorm processes.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ScintillationDetector">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which detects flouresences of
            a material which is excited by high energy
            (ionizing) electromagnetic or charged particle
            radiation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SearchCoil">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures the time variation
            of the magnetic flux threading a loop by measurement
            of the electric potential difference induced
            between the ends of the wire.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Sounder">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures the radiances
            from an object. A sounder may measure radiances
            at multiple spectral ranges.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SpacecraftPotentialControl">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument to control the electric potential
            of a spacecraft with respect to the ambient
            plasma by emitting a variable current of positive
            ions.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SpectralPowerReceiver">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A radio receiver which determines the power
            spectral density of the electric or magnetic
            field, or both, at one or more frequencies.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Spectrometer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument that measures the component
            wavelengths of light (or other electromagnetic
            radiation) by splitting the light up into
            its component wavelengths.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TimeOfFlight">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An instrument which measures the time it takes
            for a particle to travel between two detectors.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Unspecified">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A value which is not provided.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="WaveformReceiver">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A radio receiver which outputs the value of
            one or more components of the electric and/or
            magnetic field as a function of time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Integral

Identifiers for values above a given threshold
and over area or solid-angle range.
========================== -->
   <xsd:simpleType name="enumIntegral">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for values above a given threshold
               and over area or solid-angle range.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Area">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Integration over the extent of a planar region,
            or of the surface of a solid.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Bandwidth">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Integration over the width a frequency band.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SolidAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Integration over the angle in three-dimensional
            space that an object subtends at a point.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Ionosphere

Identifiers for ionospheric regions.
========================== -->
   <xsd:simpleType name="enumIonosphere">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for ionospheric regions.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="DRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the ionosphere that exists approximately
            50 to 95 km above the surface of the Earth.
            One of several layers in the ionosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ERegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A layer of ionised gas occurring at 90-150km
            above the ground. One of several layers in
            the ionosphere. Also called the The Kennelly-Heaviside
            layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A layer that contains ionized gases at a height
            of around 150-800 km above sea level, placing
            it in the thermosphere. the F region has the
            highest concentration of free electrons and
            ions anywhere in the atmosphere. It may be
            thought of as comprising two layers, the F1-and
            F2-layers. One of several layers in the ionosphere.
            Also known as the Appleton layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Topside">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region at the upper most areas of the
            ionosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Magnetosphere

Identifiers for the region of space above
the atmosphere or surface of the planet, and
bounded by the magnetopause, that is under
the direct influence of planet's magnetic
field.
========================== -->
   <xsd:simpleType name="enumMagnetosphere">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the region of space above
               the atmosphere or surface of the planet, and
               bounded by the magnetopause, that is under
               the direct influence of planet's magnetic
               field.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Magnetotail">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region on the night side of the body where
            the magnetic filed is stretched backwards
            by the force of the solar wind. For Earth,
            the magnetotail begins at a night-side radial
            distance of 10 Re (X &gt; -10Re).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Main">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the magnetosphere where the
            magnetic field lines are closed, but does
            not include the gaseous region gravitationally
            bound to the body.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Polar">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region near the pole of a body. For a
            magnetosphere the polar region is the area
            where magnetic field lines are open and includes
            the auroral zone.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="RadiationBelt">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region within a magnetosphere where high-energy
            particles could potentially be trapped in
            a magnetic field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Measurement Type

Identifiers for the method of making an estimated
value of a quantity that forms the basis of
an observation.
========================== -->
   <xsd:simpleType name="enumMeasurementType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the method of making an estimated
               value of a quantity that forms the basis of
               an observation.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Current">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		Direct measurement of the electric curreny
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ActivityIndex">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An indication, derived from one or more measurements,
            of the level of activity of an object or region,
            such as sunspot number, F10.7 flux, Dst, or
            the Polar Cap Indices.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Dopplergram">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A map or image depicting the spatial distribution
            of line-of-sight velocities of the observed
            object.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Dust">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Free microscopic particles of solid material.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ElectricField">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region of space around a charged particle,
            or between two voltages within which a force
            is exerted on charged objects in its vicinity.
            An electric field is the electric force per
            unit charge.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EnergeticParticles">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Pieces of matter that are moving very fast.
            Energetic particles include protons, electrons,
            neutrons, neutrinos, the nuclei of atoms,
            and other sub-atomic particles.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ephemeris">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The spatial coordinates of a body as a function
            of time. When used as an Instrument Type it
            represents the process or methods used to
            generate spatial coordinates.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ImageIntensity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Measurements of the two-dimensional distribution
            of the intensity of photons from some region
            or object such as the Sun or the polar auroral
            regions; can be in any wavelength band, and
            polarized, etc.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="InstrumentStatus">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A quantity directly related to the operation
            or function of an instrument.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="IonComposition">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            In situ measurements of the relative flux
            or density of electrically charged particles
            in the space environment. May give simple
            fluxes, but full distribution functions are
            sometimes measured.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Irradiance">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Irradiance - A radiometric term for the power
            of electromagnetic radiation at a surface,
            per unit area. "Irradiance" is used when the
            electromagnetic radiation is incident on the
            surface.  Irradiance data may be reported
            in any units (i.e. counts/s) due to, for example,
            being at a particular wavelength, or to being
            a not-fully-calibrated relative measurement.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MagneticField">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region of space near a magnetized body where
            magnetic forces can be detected (as measured
            by methods such as Zeeman splitting, etc.).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnetogram">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Measurements of the vector or line-of-sight
            magnetic field determined from remote sensing
            measurements of the detailed structure of
            spectral lines, including their splitting
            and polarization. ("Magnetogram.")
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NeutralAtomImages">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Measurements of neutral atom fluxes as a function
            of look direction; often related to remote
            energetic charged particles that lose their
            charge through charge-exchange and then reach
            the detector on a line-of-sight trajectory.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NeutralGas">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Measurements of neutral atomic and molecular
            components of a gas.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Profile">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Measurements of a quantity as a function of
            height above an object such as the limb of
            a body.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Radiance">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A radiometric measurement that describes the
            amount of electromagnetic radiation that passes
            through or is emitted from a particular area,
            and falls within a given solid angle in a
            specified direction. They are used to characterize
            both emission from diffuse sources and reflection
            from diffuse surfaces.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Spectrum">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The distribution of a characteristic of a
            physical system or phenomenon, such as the
            energy emitted by a radiant source, arranged
            in the order of wavelengths.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ThermalPlasma">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Measurements of the plasma in the energy regime
            where the most of the plasma occurs. May be
            the basic fluxes in the form of distribution
            functions or the derived bulk parameters (density,
            flow velocity, etc.).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Waves">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Data resulting from observations of wave experiments
            and natural wave phenomena. Wave experiments
            are typically active and natural wave phenomena
            are passive. Examples of wave experiments
            include coherent/incoherent scatter radars,
            radio soundings, VLF propagation studies,
            ionospheric scintillation of beacon satellite
            signals, etc. Examples of natural wave phenomena
            include micropulsations, mesospheric gravity
            waves, auroral/plasmaspheric hiss, Langmuir
            waves, AKR, Jovian decametric radiation, solar
            radio bursts, etc.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Waves.Active">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Exerting an influence or producing a change
            or effect. An active measurement is one which
            produces a transmission or excitation as a
            part of the measurement cycle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Waves.Passive">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Movement or effect produced by outside influence.
            A passive measurement is one which does not
            produce a transmission or excitation as a
            part of the measurement cycle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Mixed Quantity

Identifiers for the combined attributes of
a mixed parameter quantity.
========================== -->
   <xsd:simpleType name="enumMixedQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the combined attributes of
               a mixed parameter quantity.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="AkasofuEpsilon">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the magnetopause energy flux
            and an indicator of the solar wind power available
            for subsequent magnetospheric energization.
            Defined as: V*B^2*l^2sin(theta/2)^4 where
            B is the IMF, l is an empirical scaling parameter
            equal to 7 RE, and theta = tan(BY /BZ)^-1
            the IMF clock angle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="AlfvenMachNumber">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The ratio of the bulk flow speed to the Alfven
            speed.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="AlfvenVelocity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Phase velocity of the Alfven wave; In SI units
            it is the velocity of the magnetic field divided
            by the square root of the mass density times
            the permeability of free space (mu).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FrequencyToGyrofrequencyRatio">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The ratio of the characteristic frequency
            of a medium to gyrofrequency of a particle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MagnetosonicMachNumber">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The ratio of the velocity of fast mode waves
            to the Alfven velocity.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Other">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Not classified with more specific terms. The
            context of its usage may be described in related
            text.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PlasmaBeta">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The ratio of the plasma pressure (nkT) to
            the magnetic pressure (B^2/2mu0) of the SUM(nkT)/(B^2/2mu0).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TotalPressure">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            In an MHD fluid it is the number density (N)
            times Boltzmann constant times the temperature
            in Kelvin.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="VCrossB">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The cross product of the charge velocity (V)
            and the magnetic field (B). It is the electric
            field exerted on a point charge by a magnetic
            field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Near Surface

Identifiers for regions of the gaseous and
possibly ionized environment of a body extending
from the surface to some specified altitude.
========================== -->
   <xsd:simpleType name="enumNearSurface">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for regions of the gaseous and
               possibly ionized environment of a body extending
               from the surface to some specified altitude.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Atmosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The neutral gases surrounding a body that
            extends from the surface and is bound to the
            body by virtue of the gravitational attraction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="AuroralRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region in the atmospheric where electrically-charged
            particles bombarding the upper atmosphere
            of a planet in the presence of a magnetic
            field produce an optical phenomenon.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EquatorialRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region centered on the equator and limited
            in latitude by approximately 23 degrees north
            and south of the equator.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ionosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The charged or ionized gases surrounding a
            body that are nominally bound to the body
            by virtue of the gravitational attraction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ionosphere.DRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the ionosphere that exists approximately
            50 to 95 km above the surface of the Earth.
            One of several layers in the ionosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ionosphere.ERegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A layer of ionised gas occurring at 90-150km
            above the ground. One of several layers in
            the ionosphere. Also called the The Kennelly-Heaviside
            layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ionosphere.FRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A layer that contains ionized gases at a height
            of around 150-800 km above sea level, placing
            it in the thermosphere. the F region has the
            highest concentration of free electrons and
            ions anywhere in the atmosphere. It may be
            thought of as comprising two layers, the F1-and
            F2-layers. One of several layers in the ionosphere.
            Also known as the Appleton layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ionosphere.Topside">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region at the upper most areas of the
            ionosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Mesosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the Stratosphere to a range of 80 km to 85
            km, temperature decreasing with height.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Plasmasphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region of the magnetosphere consisting of
            low energy (cool) plasma. It is located above
            the ionosphere. The outer boundary of the
            plasmasphere is known as the plasmapause,
            which is defined by an order of magnitude
            drop in plasma density.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PolarCap">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The areas of the globe surrounding the poles
            and consisting of the region north of 60 degrees
            north latitude an the region south of 60 degrees
            south latitude.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SouthAtlanticAnomalyRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region where the Earth's inner van Allen
            radiation belt makes its closest approach
            to the planet's surface. The result is that,
            for a given altitude, the radiation intensity
            is higher over this region than elsewhere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Stratosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the troposphere to about 30 km, temperature
            increases with height. The stratosphere contains
            the ozone layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Thermosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the Mesosphere to 640+ km, temperature increasing
            with height.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Troposphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The lowest layer of the atmosphere which begins
            at the surface and extends to between 7 km
            (4.4 mi) at the poles and 17 km (10.6 mi)
            at the equator, with some variation due to
            weather factors.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Particle Quantity

Identifiers for the characterization of the
physical properties of the particle.
========================== -->
   <xsd:simpleType name="enumParticleQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the characterization of the
               physical properties of the particle.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ArrivalDirection">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An angular measure of the direction from which
            an energetic particle or photon was incident
            on a detector. The angles may be measured
            in any coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="AtomicNumberDetected">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of protons in the nucleus of an
            atom as determined by a detector.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="AverageChargeState">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the composite deficit (positive)
            or excess (negative) of electrons with respect
            to protons.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ChargeState">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Charge of a fully or partially stripped ion,
            in units of the charge of a proton. Charge
            state of a bare proton = 1.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CountRate">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of events per unit time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Counts">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of detection events occurring in
            a detector over the detector accumulation
            time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Energy">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The capacity for doing work as measured by
            the capability of doing work (potential energy)
            or the conversion of this capability to motion
            (kinetic energy)
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EnergyDensity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The amount of energy per unit volume.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EnergyFlux">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The amount of energy passing through a unit
            area in a unit time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FlowSpeed">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The rate at which particles or energy is passing
            through a unit area in a unit time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FlowVelocity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The volume of matter passing through a unit
            area perpendicular to the direction of flow
            in a unit of time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Fluence">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The time integral of a flux. A fluence does
            not have any "per unit time" in its units.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Gyrofrequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of gyrations around a magnetic
            guiding center (field line) a charged particle
            makes per unit time due to the Lorentz force.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HeatFlux">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Flow of thermal energy through a gas or plasma;
            typically computed as third moment of a distribution
            function.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Mass">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The measure of inertia (mass) of individual
            objects (e.g., aerosols).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MassDensity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The mass of particles per unit volume.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MassNumber">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The total number of protons and neutrons (together
            known as nucleons) in an atomic nucleus.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NumberDensity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of particles per unit volume.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NumberFlux">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of particles passing a unit area
            in unit time, possibly also per unit energy
            (or equivalent) and/or per unit look direction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ParticleRadius">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The mean radius for a Gaussian distribution
            of particles with an axial ratio of 2 and
            a distribution width that varies as 0.5 radius.
            A value of zero means no cloud was detected.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PhaseSpaceDensity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of particles per unit volume in
            the six-dimensional space of position and
            velocity.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PlasmaFrequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A number-density-dependent characteristic
            frequency of a plasma.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Pressure">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The force per unit area exerted by a particle
            distribution or field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SonicMachNumber">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The ratio of the bulk flow speed to the speed
            of sound in the medium.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SoundSpeed">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The speed at which sound travels through a
            medium.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Temperature">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the kinetic energy of random
            motion with respect to the average. Temperature
            is properly defined only for an equilibrium
            particle distribution (Maxwellian distribution).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ThermalSpeed">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            For a Maxwellian distribution, the difference
            between the mean speed and the speed within
            which ~69% (one sigma) of all the members
            of the speed distribution occur.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Velocity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Rate of change of position. Also used for
            the average velocity of a collection of particles,
            also referred to as "bulk velocity".
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Particle Type

Identifiers for the characterization of the
kind of particle observed by the measurement.
========================== -->
   <xsd:simpleType name="enumParticleType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the characterization of the
               kind of particle observed by the measurement.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Aerosol">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A suspension of fine solid or liquid particles
            in a gas.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="AlphaParticle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A positively charged nuclear particle that
            consists of two protons and two neutrons.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Atom">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Matter consisting of a nucleus surrounded
            by electrons which has no net charge.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Dust">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Free microscopic particles of solid material.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Electron">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An elementary particle consisting of a charge
            of negative electricity equal to about 1.602
            x 10^(-19) Coulomb and having a mass when
            at rest of about 9.109534 x 10^(-28) gram.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An atom that has acquired a net electric charge
            by gaining or losing one or more electrons.(Note:
            Z&gt;2)
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Molecule">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A group of atoms so united and combined by
            chemical affinity that they form a complete,
            integrated whole, being the smallest portion
            of any particular compound that can exist
            in a free state
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Neutron">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An elementary particle that has no net charge
            and is a constituent of atomic nuclei, and
            that has a mass slightly large than a proton
            (1.673 x 10^(-24) gram.)
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Proton">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An elementary particle that is a constituent
            of all atomic nuclei, that carries a positive
            charge numerically equal to the charge of
            an electron, and that has a mass of 1.673
            x 10^(-24) gram.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Phenomenon Type

Identifiers for the characteristics or categorization
of an observation. Note: Joe King to provide.
========================== -->
   <xsd:simpleType name="enumPhenomenonType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the characteristics or categorization
               of an observation. Note: Joe King to provide.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ActiveRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A localized, transient volume of the solar
            atmosphere in which PLAGEs, SUNSPOTS, FACULAe,
            FLAREs, etc. may be observed.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Aurora">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An atmospheric phenomenon consisting of bands
            of light caused by charged solar particles
            following the earth's magnetic lines of force.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="BowShockCrossing">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A crossing of the boundary between the undisturbed
            (except for foreshock effects) solar wind
            and the shocked, decelerated solar wind of
            the magnetosheath.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CoronalHole">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An extended region of the corona, exceptionally
            low in density and associated with unipolar
            photospheric regions. A coronal hole can be
            an "open" magnetic field in the corona and
            (perhaps) inner heliosphere which has a faster
            than average outflow (wind); A region of lower
            than "quiet" ion and electron density in the
            corona; or a region of lower peak electron
            temperature in the corona than in the "quiet"
            corona.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CoronalMassEjection">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A solar event (CME) that involves a burst
            of plasma ejected into the interplanetary
            medium. CME's may be observed remotely relatively
            near the sun or in situ in the interplanetary
            medium. The latter type of observations are
            often referred to as Interplanetary CME's
            (ICME's).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EITWave">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A wave in the corona of the Sun which produce
            shock waves on the Sun's chromosphere (Moreton
            Waves). EIT Waves are produced by large solar
            flare and expand outward at about 1,000 km/s.
            It usually appears as a slowly moving diffuse
            arc of brightening in H-alpha, and may travel
            for several hundred thousand km.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EnergeticSolarParticleEvent">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An enhancement of interplanetary fluxes of
            energetic ions accelerated by interplanetary
            shocks and/or solar flares.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ForbushDecrease">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A rapid decrease in the observed galactic
            cosmic ray intensity following the passage
            of an outwardly convecting interplanetary
            magnetic field disturbance, such as those
            associated with large CME's, that sweep some
            galactic cosmic rays away from Earth.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GeomagneticStorm">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A magnetospheric disturbance typically defined
            by variations in the horizontal component
            of the Earth's surface magnetic field. The
            variation typically starts with a field enhancement
            associated with a solar wind pressure pulse
            and continues with a field depression associated
            with an enhancement of the diamagnetic magnetospheric
            ring current.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="InterplanetaryShock">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A shock propagating generally anti-sunward
            through the slower solar wind, often seen
            in front of CME-associated plasma clouds.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MagneticCloud">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A transient event observed in the solar wind
            characterized as a region of enhanced magnetic
            field strength, smooth rotation of the magnetic
            field vector and low proton density and temperature.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MagnetopauseCrossing">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A crossing of the interface between the shocked
            solar wind in the magnetosheath and the magnetic
            field and plasma in the magnetosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="RadioBurst">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Emissions of the sun in radio wavelengths
            from centimeters to dekameters, under both
            quiet and disturbed conditions. Radio Bursts
            can be "Type I" consisting of many short,
            narrow-band bursts in the metric range (300
            - 50 MHz).; "Type II" consisting of narrow-band
            emission that begins in the meter range (300
            MHz) and sweeps slowly (tens of minutes) toward
            dekameter wavelengths (10 MHz).; "Type III"
            consisting of narrow-band bursts that sweep
            rapidly (seconds) from decimeter to dekameter
            wavelengths (500 - 0.5 MHz); and "Type IV"
            consisting of a smooth continuum of broad-band
            bursts primarily in the meter range (300 -
            30 MHz).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SectorBoundaryCrossing">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sector boundary crossing is a transit by
            a spacecraft across the heliospheric current
            sheet separating the dominantly outward (away-from-the-sun)
            interplanetary magnetic field of one hemisphere
            of the heliosphere from the dominantly inward
            (toward-the-sun) polarity of the other hemisphere.
             Such crossings have multi-day intervals of
            opposite IMF dominant polarities on either
            side.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SolarFlare">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An explosive event in the Sun's atmosphere
            which produces electromagnetic radiation across
            the electromagnetic spectrum at multiple wavelengths
            from long-wave radio to the shortest wavelength
            gamma rays.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SolarWindExtreme">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Intervals of unusually large or small values
            of solar wind attributes such as flow speed
            and ion density.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="StreamInteractionRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region (SIR) where two solar wind streams,
            typically having differing characteristics
            and solar sources, abut up against (and possibly
            partially interpenetrate) each other.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Substorm">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A process by which plasma in the magnetotail
            becomes energized at a fast rate.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Processing Level

Identifiers to characterize the amount and
type of manipulation which has been applied
to the sampled data.
========================== -->
   <xsd:simpleType name="enumProcessingLevel">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers to characterize the amount and
               type of manipulation which has been applied
               to the sampled data.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Calibrated">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Data wherein sensor outputs have been convolved
            with instrument response function, often irreversibly,
            to yield data in physical units.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Raw">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Data in its original state with no processing
            to account for calibration!!!
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Uncalibrated">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Duplicate data are removed from the data stream
            and data are time ordered. Values are not
            adjusted for any potential biases or external
            factors.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Projection

Identifiers to projections into a coordinate
system.
========================== -->
   <xsd:simpleType name="enumProjection">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers to projections into a coordinate
               system.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="IJ">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the length of a position or measured
            vector projected into the i-j (typically X-Y)
            plane of the coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="IK">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the length of a position or measured
            vector projected into the i-k (typically X-Z)
            plane of the coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="JK">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the length of a position or measured
            vector projected into the j-k (typically Y-Z)
            plane of the coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Qualifier

Identifiers for terms which refine the type
or attribute of a quantity.
========================== -->
   <xsd:simpleType name="enumImpexSpecialRegion">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">Special Region keyword related to areas in the simulation "world"</xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Incident">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
                  Direction-dependent property.
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <xsd:simpleType name="enumQualifier">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for terms which refine the type
               or attribute of a quantity.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Anisotropy">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Direction-dependent property.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Array">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sequence of values corresponding to the
            elements in a rectilinear, n-dimension matrix.
            Each value can be referenced by a unique index.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Average">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The statistical mean; the sum of a set of
            values divided by the number of values in
            the set.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Characteristic">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A quantity which can be easily identified
            and measured in a given environment.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Circular">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Relative to polarization, right-hand circularly
            polarized light is defined such that the electric
            field is rotating clockwise as seen by an
            observer towards whom the wave is moving.
            Left-hand circularly polarized light is defined
            such that the electric field is rotating counterclockwise
            as seen by an observer towards whom the wave
            is moving. The polarization of magnetohydrodynamic
            waves is specified with respect to the ambient
            mean magnetic field : right-hand polarized
            waves have a transverse electric field component
            which turns in a right-handed sense (that
            of the gyrating electrons) around the magnetic
            field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Column">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A two-dimensional measure of a quantity. The
            column is the area over which the quantity
            is measured.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Component">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Projection of a vector along one of the base
            axes of a coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Component.I">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Projection of a vector along the first named
            axis of a coordinate system. Typically the
            X axis, but could be the R axis for an RTN
            coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Component.J">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Projection of a vector along the second named
            axis of a coordinate system. Typically the
            Y axis, but could be the T axis for an RTN
            coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Component.K">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Projection of a vector along the third named
            axis of a coordinate system. Typically the
            Z axis, but could be the N axis for an RTN
            coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Core">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The central or main part of an object or calculated
            distribution. For example, the part of a distribution
            of particles at low energies that is a thermal
            (Maxwellian) population. 
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CrossSpectrum">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The Fourier transform of the cross correlation
            of two physical or empirical observations.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Deviation">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The difference between an observed value and
            the expected value of a quantity.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Differential">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measurement within a narrow range of energy
            and/or solid angle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Direction">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The spatial relation between an object and
            another object, the orientation of the object
            or the course along which the object points
            or moves.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DirectionAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The angle between a position vector or measured
            vector (or one of its projections onto a plane)
            and one of the base axes of the coordinate
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DirectionAngle.AzimuthAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The angle between the projection into the
            i-j plane of a position or measured vector
            and the i-axis of the coordinate system. Mathematically
            defined as arctan(j/i).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DirectionAngle.ElevationAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The angle between the position or measured
            vector and the i-j plane of the coordinate
            system. Mathematically defined as arctan(k/SQRT(i^2+j^2)).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DirectionAngle.PolarAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The angle between the position or measured
            vector and the k-axis of the coordinate system.
            Mathematically defined as arctan([SQRT(i^2+j^2)]/k).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Directional">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measurement within a narrow range of solid
            angle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FieldAligned">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The component of a quantity which is oriented
            in the same direction of a field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Fit">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Values that make an model agree with the data.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Group">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An assemblage of values that a certain relation
            or common characteristic.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Halo">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The part of an object or distribution surrounding
            some central body or distribution.  For example,
            the particles above the core energies that
            show enhancements above the thermal population.
             Typically, a "power law tail" shows a break
            from the core Maxwellian at a particular energy.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Integral">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A flux measurement in a broad range of energy
            and solid angle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Integral.Area">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Integration over the extent of a planar region,
            or of the surface of a solid.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Integral.Bandwidth">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Integration over the width a frequency band.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Integral.SolidAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Integration over the angle in three-dimensional
            space that an object subtends at a point.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="LineOfSight">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The line of sight is the line that connects
            the observer with the observed object. This
            expression is often used with measurements
            of Doppler velocity and magnetic field in
            magnetograms, where only the component of
            the vector field directed along the line of
            sight is measured.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Linear">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Polarization where the E-field vector is confined
            to a given plane
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Magnitude">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the strength of a vector quantity
            or length of its representational vector.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Maximum">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The largest value of a batch or sample or
            the upper bound of a probability distribution.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Median">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The measure of central tendency of a set of
            n. values computed by ordering the values
            and taking the value at position (n.  + 1)
            / 2 when n. is odd or the arithmetic mean
            of the values at positions n.  / 2 and (n.
            / 2) + 1 when n.  is even.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Minimum">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The smallest value of a batch or sample or
            the lower bound of a probability distribution.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Moment">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Parameters determined by integration over
            a distribution function convolved with a power
            of velocity.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Parallel">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Having the same direction as a given direction
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Peak">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The maximum value for the quantity in question,
            over a period of time which is usually equal
            to the cadence.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Perpendicular">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            At right angles to a given direction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Perturbation">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Variations in the state of a system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Phase">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A point or portion in a recurring series of
            changes.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PhaseAngle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Phase difference between two or more waves,
            normally expressed in degrees.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Projection">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the length of a position or measured
            vector as projected into a plane of the coordinate
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Projection.IJ">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the length of a position or measured
            vector projected into the i-j (typically X-Y)
            plane of the coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Projection.IK">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the length of a position or measured
            vector projected into the i-k (typically X-Z)
            plane of the coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Projection.JK">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of the length of a position or measured
            vector projected into the j-k (typically Y-Z)
            plane of the coordinate system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Pseudo">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Similar to or having the appearance of something
            else. Can be used to indicate an estimation
            or approximation of a particular quantity.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ratio">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The relative magnitudes of two quantities.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Scalar">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A quantity that is completely specified by
            its magnitude and has no direction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Spectral">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Characterized as a range or continuum of frequencies
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="StandardDeviation">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The square root of the average of the squares
            of deviations about the mean of a set of data.
            Standard deviation is a statistical measure
            of spread or variability.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="StokesParameters">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A set of four parameters (usually called I,Q,
            U and V) which describe the polarization state
            of an electromagnetic wave propagating through
            space.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Strahl">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A distribution of particles concentrated in
            a narrow energy band. The band may be may
            be aligned with a secondary feature. For example,
            it may occur in a narrow cone aligned with
            the mean magnetic field direction. 
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Superhalo">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The part of an object or distribution surrounding
            some central body or distribution evident
            in a second break in the distribution function
            (e.g., a different power law).  It consists
            of a population at a higher energies than
            for a halo.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Symmetric">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Equal distribution about one or more axes.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Tensor">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A generalized linear "quantity" or "geometrical
            entity" that can be expressed as a multi-dimensional
            array relative to a choice of basis of the
            particular space on which it is defined.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Total">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The summation of quantities over all possible
            species.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Trace">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The sum of the elements on the main diagonal
            (the diagonal from the upper left to the lower
            right) of a square matrix.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Uncertainty">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A statistically defined discrepancy between
            a measured quantity and the true value of
            that quantity that cannot be corrected by
            calculation or calibration.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Variance">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A measure of dispersion of a set of data points
            around their mean value. The expectation value
            of the squared deviations from the mean.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Vector">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A set of parameter values each along some
            independent variable (e.g., components of
            a field in three orthogonal spatial directions;
            atmospheric temperature values at several
            altitudes, or at a given latitude and longitude;).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Region

Identifiers for areas of the physical world
which may be occupied or observed.
========================== -->
   <xsd:simpleType name="enumRegion">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for areas of the physical world
               which may be occupied or observed.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Asteroid">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A small extraterrestrial body consisting mostly
            of rock and metal that is in orbit around
            the sun.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Callisto">
            <xsd:annotation>
               <xsd:documentation>A moon of the planet Jupiter, the second largest after Ganymede and the third-largest in the solar system </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Comet">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A relatively small extraterrestrial body consisting
            of a frozen mass that travels around the sun
            in a highly elliptical orbit.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The third planet from the sun in our solar
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.Magnetosheath">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region between the bow shock and the magnetopause,
            characterized by very turbulent plasma.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.Magnetosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of space above the atmosphere or
            surface of the planet, and bounded by the
            magnetopause, that is under the direct influence
            of the planet's magnetic field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.Magnetosphere.Magnetotail">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region on the night side of the body where
            the magnetic filed is stretched backwards
            by the force of the solar wind. For Earth,
            the magnetotail begins at a night-side radial
            distance of 10 Re (X &gt; -10Re).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.Magnetosphere.Main">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the magnetosphere where the
            magnetic field lines are closed, but does
            not include the gaseous region gravitationally
            bound to the body.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.Magnetosphere.Polar">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region near the pole of a body. For a
            magnetosphere the polar region is the area
            where magnetic field lines are open and includes
            the auroral zone.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.Magnetosphere.RadiationBelt">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region within a magnetosphere where high-energy
            particles could potentially be trapped in
            a magnetic field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The gaseous and possibly ionized environment
            of a body extending from the surface to some
            specified altitude. For the Earth, this altitude
            is 2000 km.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Atmosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The neutral gases surrounding a body that
            extends from the surface and is bound to the
            body by virtue of the gravitational attraction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.AuroralRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region in the atmospheric where electrically-charged
            particles bombarding the upper atmosphere
            of a planet in the presence of a magnetic
            field produce an optical phenomenon.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.EquatorialRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region centered on the equator and limited
            in latitude by approximately 23 degrees north
            and south of the equator.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Ionosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The charged or ionized gases surrounding a
            body that are nominally bound to the body
            by virtue of the gravitational attraction.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Ionosphere.DRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the ionosphere that exists approximately
            50 to 95 km above the surface of the Earth.
            One of several layers in the ionosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Ionosphere.ERegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A layer of ionised gas occurring at 90-150km
            above the ground. One of several layers in
            the ionosphere. Also called the The Kennelly-Heaviside
            layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Ionosphere.FRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A layer that contains ionized gases at a height
            of around 150-800 km above sea level, placing
            it in the thermosphere. the F region has the
            highest concentration of free electrons and
            ions anywhere in the atmosphere. It may be
            thought of as comprising two layers, the F1-and
            F2-layers. One of several layers in the ionosphere.
            Also known as the Appleton layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Ionosphere.Topside">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region at the upper most areas of the
            ionosphere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Mesosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the Stratosphere to a range of 80 km to 85
            km, temperature decreasing with height.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Plasmasphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region of the magnetosphere consisting of
            low energy (cool) plasma. It is located above
            the ionosphere. The outer boundary of the
            plasmasphere is known as the plasmapause,
            which is defined by an order of magnitude
            drop in plasma density.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.PolarCap">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The areas of the globe surrounding the poles
            and consisting of the region north of 60 degrees
            north latitude an the region south of 60 degrees
            south latitude.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.SouthAtlanticAnomalyRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region where the Earth's inner van Allen
            radiation belt makes its closest approach
            to the planet's surface. The result is that,
            for a given altitude, the radiation intensity
            is higher over this region than elsewhere.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Stratosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the troposphere to about 30 km, temperature
            increases with height. The stratosphere contains
            the ozone layer.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Thermosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The layer of the atmosphere that extends from
            the Mesosphere to 640+ km, temperature increasing
            with height.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.NearSurface.Troposphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The lowest layer of the atmosphere which begins
            at the surface and extends to between 7 km
            (4.4 mi) at the poles and 17 km (10.6 mi)
            at the equator, with some variation due to
            weather factors.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Earth.Surface">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The outermost area of a solid object.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Enceladus">
            <xsd:annotation>
               <xsd:documentation>One of the innermost moons of Saturn.</xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Europa">
            <xsd:annotation>
               <xsd:documentation>The sixth-closest moon of the planet Jupiter</xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ganymede">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
                  The biggest moon of Jupiter planet in our solar
                  system.
               </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Heliosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The solar atmosphere extending roughly from
            the outer corona to the edge of the solar
            plasma at the heliopause separating primarily
            solar plasma from interstellar plasma.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Heliosphere.Heliosheath">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region extending radially outward from
            the heliospheric termination shock and in
            which the decelerated solar wind plasma is
            still significant.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Heliosphere.Inner">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the heliosphere extending radially
            outward from the solar coronal base to just
            inside 1 AU.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Heliosphere.NearEarth">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The heliospheric region near the Earth which
            extends to and includes the area near the
            L1 and L2 Lagrange point.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Heliosphere.Outer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the heliosphere extending radially
            outward from just outside 1 AU to the heliospheric
            termination shock.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Heliosphere.Remote1AU">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A roughly toroidal region that includes the
            Earth's orbit, but exclusive of the region
            near the Earth.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Interstellar">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region between stars outside of the star's
            heliopause.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Io">
            <xsd:annotation>
               <xsd:documentation>The innermost of the four Galilean moons of the planet Jupiter </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Jupiter">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The fifth planet from the sun in our solar
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Mars">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The forth planet from the sun in our solar
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Mercury">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The first planet from the sun in our solar
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Neptune">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The seventh planet from the sun in our solar
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Pluto">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The ninth (sub)planet from the sun in our
            solar system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Rhea">
            <xsd:annotation>
               <xsd:documentation>The second-largest moon of Saturn and the ninth largest moon in the Solar System</xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Saturn">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The sixth planet from the sun in our solar
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Sun">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The star upon which our solar system is centered.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Sun.Chromosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the Sun's (or a star's) atmosphere
            above the temperature minimum and below the
            Transition Region. The solar chromosphere
            is approximately 400 km to 2100 km above the
            photosphere, and characterized by temperatures
            from 4500 - 28000 K.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Sun.Corona">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The outermost atmospheric region of the Sun
            or a star, characterized by ionization temperatures
            above 10^5 K. The solar corona starts at about
            2100 km above the photosphere; there is no
            generally defined upper limit.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Sun.Interior">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region inside the body which is not visible
            from outside the body.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Sun.Photosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The atmospheric layer of the Sun or a star
            from which continuum radiation, especially
            optical, is emitted to space. For the Sun,
            the photosphere is about 500 km thick.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Sun.TransitionRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A very narrow (&lt;100 km) layer between the
            chromosphere and the corona where the temperature
            rises abruptly from about 8000 to about 500,000
            K.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Titan">
            <xsd:annotation>
               <xsd:documentation>The largest moon of Saturn</xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Uranus">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The eighth planet from the sun in our solar
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Venus">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The second planet from the sun in our solar
            system.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Rendering Axis

Identifiers for the reference component of
a plot or rendering of data.
========================== -->
   <xsd:simpleType name="enumRenderingAxis">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the reference component of
               a plot or rendering of data.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ColorBar">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum or set of colors used to represent
            data values.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Horizontal">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Parallel to or in the plane of the horizon
            or a base line.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Vertical">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Perpendicular to the plane of the horizon
            or a base line.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Role

Identifiers for the assigned or assumed function
or position of an individual.
========================== -->
   <xsd:simpleType name="enumRole">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the assigned or assumed function
               or position of an individual.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ArchiveSpecialist">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who is an expert on a collection
            of resources and may also be knowledgeable
            of the phenomenon and related physics represented
            by the resources. This includes librarians,
            curators, archive scientists and other experts.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="CoInvestigator">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who is a scientific peer and
            major participant in an investigation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Contributor">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An entity responsible for making contributions
            to the content of the resource.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DataProducer">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who generated the resource and
            is familiar with its provenance.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DeputyPI">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who is an administrative or
            scientific leader for an investigation operating
            under the supervision of a Principal Investigator.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FormerPI">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who had served as the administrative
            and scientific lead for an investigation,
            but no longer assumes that role.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GeneralContact">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who can provide information
            on a range of subjects or who can direct you
            to a domain expert.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MetadataContact">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who can affect a change in the
            metadata describing a resource.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PrincipalInvestigator">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who is the administrative and
            scientific lead for an investigation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ProjectScientist">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who is an expert in the phenomenon
            and related physics explored by the project.
            A project scientist may also have a managerial
            role within the project.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Publisher">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual, organization, institution or
            government department responsible for the
            production and dissemination of a document.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Scientist">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who is an expert in the phenomenon
            and related physics represented by the resource.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TeamLeader">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who is the designated leader
            of an investigation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TeamMember">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who is a major participant in
            an investigation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TechnicalContact">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An individual who can provide specific information
            with regard to the resource or supporting
            software
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Scale Type

Identifiers for scaling applied to a set of
numbers.
========================== -->
   <xsd:simpleType name="enumScaleType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for scaling applied to a set of
               numbers.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="LinearScale">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Intervals which are equally spaced.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="LogScale">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Intervals which are spaced proportionally
            to the logarithms of the values being represented.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Source Type

Identifiers for the characterization of the
function or purpose of a source.
========================== -->
   <xsd:simpleType name="enumSourceType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the characterization of the
               function or purpose of a source.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Ancillary">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A complementary item which can be subordinate,
            subsidiary, auxiliary, supplementary to the
            primary item.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Browse">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A representation of an image which is suitable
            to reveal most or all of the details of the
            image.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Data">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A collection of organized information, usually
            the results of experience, observation or
            experiment, or a set of premises. This may
            consist of numbers, words, or images, particularly
            as measurements or observations of a set of
            variables.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Layout">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The structured arrangement of items in a collection.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Thumbnail">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A small representation of an image which is
            suitable to infer what the full-sized imaged
            is like.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Spectral Range

Identifiers for names associated with wavelengths.
Based on the ISO 21348 Solar Irradiance Standard.
Additions have been made to extend the frequency
ranges to include those used in space physics.
Those additions are indicated in blue text.
The "Total Solar Irradiance" category has
not been included since it is a type of measurement
and not a specific spectral range. See Appendix
A - Comparison of Spectrum Domains for a comparison
of the spectral ranges with other systems.
========================== -->
   <xsd:simpleType name="enumSpectralRange">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for names associated with wavelengths.
               Based on the ISO 21348 Solar Irradiance Standard.
               Additions have been made to extend the frequency
               ranges to include those used in space physics.
               Those additions are indicated in blue text.
               The "Total Solar Irradiance" category has
               not been included since it is a type of measurement
               and not a specific spectral range. See Appendix
               A - Comparison of Spectrum Domains for a comparison
               of the spectral ranges with other systems.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="CaK">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum with a wavelength of range centered
            near 393.5 nm. VSO nickname: Ca-K image with
            range of 391.9 nm to 395.2 nm.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ExtremeUltraviolet">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum with a wavelength range of 10.0
            nm to 125.0nm. VSO nickname: EUV image with
            a range of of 10.0 nm to 125.0 nm
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="FarUltraviolet">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum with a wavelength range of 122
            nm to 200.0nm. VSO nickname: FUV image with
            a range of 122.0 nm to 200 nm
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="GammaRays">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength range: 0.00001 to
            0.001 nm
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Halpha">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum with a wavelength range centered
            at 656.3 nm. VSO nickname: H-alpha image with
            a spectrum range of of 655.8 nm to 656.8 nm.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="HardXrays">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength range: 0.001 to
            0.1 nm and an energy range of 12 keV to 120
            keV
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="He10830">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum with a wavelength range centered
            at 1082.9 nm. VSO nickname: He 10830 image
            with a range of 1082.5 nm to 1083.3 nm.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="He304">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum centered around the resonance line
            of ionised helium at 304 Angstrom (30.4 nm).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Infrared">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength range: 760 to 1.00x10^6
            nm
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="K7699">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum with a wavelength range centred
            at 769.9 nm. VSO nickname: K-7699 dopplergram
            with a range of 769.8 nm to 770.0 nm.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="LBHBand">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Lyman-Birge-Hopfield band in the far ultraviolet
            range with wavelength range of 140nm to 170
            nm.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Microwave">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength range: 1.00x10^6
            to 1.50x10^7 nm
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="NaD">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum with a wavelength range of centered
            at 589.3 nm. VSO nickname: Na-D image with
            a range of 588.8 nm to 589.8 nm.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ni6768">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A spectrum with a wavelength range centered
            at 676.8 nm. VSO nickname: Ni-6768 dopplergram
            with a range of of 676.7 nm to 676.9 nm.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Optical">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength range: 380 to 760
            nm
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="RadioFrequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength range: 100,000 to
            1.00x10^11 nm
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="SoftXRays">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            X-Rays with an energy range of 0.12 keV to
            12 keV.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Ultraviolet">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength range: 10 to 400
            nm.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="WhiteLight">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength in the visible range
            for humans.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="XRays">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Photons with a wavelength range: 0.001 &lt;=
            x &lt; 10 nm
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Sun

Identifiers for regions of the star upon which
our solar system is centered.
========================== -->
   <xsd:simpleType name="enumSun">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for regions of the star upon which
               our solar system is centered.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Chromosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region of the Sun's (or a star's) atmosphere
            above the temperature minimum and below the
            Transition Region. The solar chromosphere
            is approximately 400 km to 2100 km above the
            photosphere, and characterized by temperatures
            from 4500 - 28000 K.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Corona">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The outermost atmospheric region of the Sun
            or a star, characterized by ionization temperatures
            above 10^5 K. The solar corona starts at about
            2100 km above the photosphere; there is no
            generally defined upper limit.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Interior">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The region inside the body which is not visible
            from outside the body.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Photosphere">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The atmospheric layer of the Sun or a star
            from which continuum radiation, especially
            optical, is emitted to space. For the Sun,
            the photosphere is about 500 km thick.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="TransitionRegion">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A very narrow (&lt;100 km) layer between the
            chromosphere and the corona where the temperature
            rises abruptly from about 8000 to about 500,000
            K.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Support Quantity

Identifiers for the information useful in
understanding the context of an observation,
typically observed or measured coincidentally
with a physical observation.
========================== -->
   <xsd:simpleType name="enumSupportQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the information useful in
               understanding the context of an observation,
               typically observed or measured coincidentally
               with a physical observation.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="InstrumentMode">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            An indication of a state (mode) in which the
            instrument is operating. How a mode influences
            the interpretation and representation of data
            is described in instrument related documentation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Other">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Not classified with more specific terms. The
            context of its usage may be described in related
            text.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Positional">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The specification of the location of an object
            or measurement within a reference coordinate
            system. The position is usually expressed
            as a set of values corresponding to the location
            along a set of orthogonal axes together with
            the date/time of the observation.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Temporal">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Pertaining to time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Velocity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Rate of change of position. Also used for
            the average velocity of a collection of particles,
            also referred to as "bulk velocity".
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Text

Identifiers for the encoding of sequences
of characters.
========================== -->
   <xsd:simpleType name="enumText">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the encoding of sequences
               of characters.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ASCII">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A sequence of characters that adheres to American
            Standard Code for Information Interchange
            (ASCII) which is an 7-bit character-coding
            scheme.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Unicode">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Text in multi-byte Unicode format.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Wave Quantity

Identifiers for the characterization of the
physical properties of a wave.
========================== -->
   <xsd:simpleType name="enumWaveQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the characterization of the
               physical properties of a wave.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ACElectricField">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Alternating electric field component of a
            wave.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ACMagneticField">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Alternating magnetic field component of a
            wave.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Absorption">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Decrease of radiant energy (relative to the
            background continuum spectrum).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Albedo">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The ratio of reflected radiation from the
            surface to incident radiation upon it.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DopplerFrequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Change in the frequency of a propagating wave
            due to motion of the source, the observer,
            the reflector, or the propagation medium.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Emissivity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The energy emitted spontaneously per unit
            bandwidth (typically frequency) per unit time
            per unit mass of source. Emissivity is usually
            integrated over all directions/solid angles.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EnergyFlux">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The amount of energy passing through a unit
            area in a unit time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="EquivalentWidth">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The spectral width of a total absorption line
            having the amount of absorbed radiant energy
            being equivalent to that in an observed absorption
            line.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Frequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of occurrences of a repeating event
            per unit time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Gyrofrequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The number of gyrations around a magnetic
            guiding center (field line) a charged particle
            makes per unit time due to the Lorentz force.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Intensity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The measurement of radiant or wave energy
            per unit detector area per unit bandwidth
            per unit solid angle per unit time.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="LineDepth">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The measure of the amount of absorption below
            the continuum (depth) in a particular wavelength
            or frequency in an absorption spectrum.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MagneticField">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A region of space near a magnetized body where
            magnetic forces can be detected (as measured
            by methods such as Zeeman splitting, etc.).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ModeAmplitude">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            In helioseismology the magnitude of oscillation
            of waves of a particular geometry.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PlasmaFrequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A number-density-dependent characteristic
            frequency of a plasma.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Polarization">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Direction of the electric vector of an electromagnetic
            wave. The wave can be linearly polarized in
            any direction perpendicular to the direction
            of travel, circularly polarized (clockwise
            or counterclockwise), unpolarized, or mixtures
            of the above.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PoyntingFlux">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Electromagnetic energy flux transported by
            a wave characterized as the rate of energy
            transport per unit area per steradian.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PropagationTime">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Time difference between transmission and reception
            of a wave in an active wave experiment.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="StokesParameters">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A set of four parameters (usually called I,Q,
            U and V) which describe the polarization state
            of an electromagnetic wave propagating through
            space.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Velocity">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Rate of change of position. Also used for
            the average velocity of a collection of particles,
            also referred to as "bulk velocity".
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Wavelength">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            The peak-to-peak distance over one wave period.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Wave Type

Identifiers for the carrier or phenomenum
of wave information observed by the measurement.
========================== -->
   <xsd:simpleType name="enumWaveType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the carrier or phenomenum
               of wave information observed by the measurement.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Electromagnetic">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Electric and magnetic field variations in
            time and space that propagate through a medium
            or a vacuum with the wave's propagation, electric
            field, and magnetic field vectors forming
            an orthogonal triad. Waves in this category
            are detected by having their field quantities
            measured.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Electrostatic">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Collective longitudinal electric-field and
            plasma oscillations trapped within a body
            of plasma.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Hydrodynamic">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Periodic or quasi-periodic oscillations of
            fluid quantities.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MHD">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Hydrodynamic waves in a magnetized plasma
            in which the background magnetic field plays
            a key role in controlling the wave propagation
            characteristics.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Photon">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Electromagnetic waves detected by techniques
            that utilize their corpuscular character (e.g.,
            CCD, CMOS, photomultipliers).
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PlasmaWaves">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Self-consistent collective oscillations of
            particles and fields (electric and magnetic)
            in a plasma.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ==========================
Waves

Identifiers for experimental and natural wave
phenomena.
========================== -->
   <xsd:simpleType name="enumWaves">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for experimental and natural wave
               phenomena.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Active">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Exerting an influence or producing a change
            or effect. An active measurement is one which
            produces a transmission or excitation as a
            part of the measurement cycle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Passive">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            Movement or effect produced by outside influence.
            A passive measurement is one which does not
            produce a transmission or excitation as a
            part of the measurement cycle.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <!-- ================================
      Types
     ================================ -->
   <xsd:simpleType name="typeSequence">
      <xsd:list itemType="xsd:integer"/>
   </xsd:simpleType>


   <!-- ============================================
      Redefinition of a few top level Spase elements
     =============================================== -->

   <xsd:element name="Granule" type="Granule" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="Granule">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               An accessible portion of another resource.
               A Granule may be composed of one or more physical
               pieces (files) which are considered inseparable.
               For example, a data storage format that maintains
               metadata and binary data in separate, but
               tightly coupled files. Granules should not
               be used to group files that have simple relationships
               or which are associated through a parent resource.
               For example, each file containing a time interval
               data for a Numerical Data resource would each
               be considered a Granule. The ParentID of a
               Granule resource must be a NumericalData resource.
               The attributes of a Granule supersede the
               corresponding attributes in the NumericalData
               resource.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ReleaseDate" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ExpirationDate" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ParentID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="PriorID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:choice>
            <xsd:element ref="StartDate" minOccurs="1" maxOccurs="1"/>
            <xsd:element ref="RegionBegin"/>
         </xsd:choice>
         <xsd:choice minOccurs="0">
            <xsd:element ref="StopDate" minOccurs="1" maxOccurs="1"/>
            <xsd:element ref="RegionEnd" minOccurs="1"/>
         </xsd:choice>
         <xsd:element ref="Source" minOccurs="1" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="NumericalOutput" type="NumericalOutput" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="NumericalOutput">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Data stored as numerical values in a specified
               format. A Numerical Data resource is a type
               of "data product" which is a set of data that
               is uniformly processed and formatted, from
               one or more instruments, typically spanning
               the full duration of the observations of the
               relevant instrument(s). A data product may
               consist of a collection of granules of successive
               time spans, but may be a single high-level
               entity.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessInformation" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="ProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderResourceName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderVersion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SimulatedInstrumentID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="MeasurementType" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:choice>
            <xsd:element ref="TemporalDescription" minOccurs="0" maxOccurs="1"/>
            <xsd:element ref="SpatialDescription" minOccurs="0" maxOccurs="1"/>
         </xsd:choice>
         <xsd:element ref="SpectralRange" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="SimulatedRegion" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Keyword" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="InputResourceID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Parameter" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="SimulationProduct"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Property"/>
         <xsd:element minOccurs="0" ref="Extension"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="DisplayOutput" type="DisplayOutput" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="DisplayOutput">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A graphical representation of data wherein
               the underlying numeric values are not (readily)
               accessible for analysis.. Examples are line
               plots and spectrograms. A Display Data resource
               is a type of "data product" which is a set
               of data that is uniformly processed and formatted,
               from one or more instruments, typically spanning
               the full duration of the observations of the
               relevant instrument(s). A data product may
               consist of a collection of granules of successive
               time spans, but may be a single high-level
               entity.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessInformation" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="ProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderResourceName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderVersion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SimulatedInstrumentID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="MeasurementType" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:choice>
            <xsd:element ref="TemporalDescription" minOccurs="0" maxOccurs="1"/>
            <xsd:element ref="SpatialDescription" minOccurs="0" maxOccurs="1"/>
         </xsd:choice>
         <xsd:element ref="SpectralRange" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="DisplayCadence" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SimulatedRegion" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Keyword" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="InputResourceID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="Parameter" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="SimulationProduct"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Property"/>
         <xsd:element minOccurs="0" ref="Extension"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="SimulationModel" type="SimulationModel" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="SimulationModel">
      <xsd:annotation>
         <xsd:documentation>Descriptor of a simulation model: type of numerical scheme, versions,...</xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element name="Versions" type="Versions" minOccurs="0"/>
         <xsd:element ref="SimulationType" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="CodeLanguage" minOccurs="0" maxOccurs="1"/>
         <xsd:element minOccurs="0" ref="TemporalDependence"/>
         <xsd:element minOccurs="0" ref="SpatialDescription"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="SimulatedRegion"/>
         <xsd:element minOccurs="0" ref="InputProperties"/>
         <xsd:element minOccurs="0" ref="OutputParameters"/>
         <xsd:element minOccurs="0" ref="ModelURL"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="InputProperties" type="InputProperties"/>
   <xsd:complexType name="InputProperties">
      <xsd:sequence>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Property"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="OutputParameters" type="OutputParameters"/>
   <xsd:complexType name="OutputParameters">
      <xsd:sequence>
         <xsd:element ref="Parameter" maxOccurs="unbounded" minOccurs="0"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="SimulationRun" type="SimulationRun" substitutionGroup="ResourceEntity"/>
   <xsd:complexType name="SimulationRun">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
	       Description of a simulation run, including the
	       code ID, the run spatial and temporal description,
	       and all the relevant inputs.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ResourceID" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="ResourceHeader" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="AccessInformation" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ProviderResourceName" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderProcessingLevel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProviderVersion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Model"/>
         <xsd:element ref="TemporalDependence" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SimulatedRegion" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="LikelihoodRating"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Keyword" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="InputResourceID" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="SimulationTime"/>
         <xsd:element ref="SimulationDomain"/>
         <xsd:element ref="InputEntity" minOccurs="1" maxOccurs="unbounded"/>
         <xsd:element ref="Extension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="VersionID" type="xsd:string"/>
   <xsd:element name="Model" type="Model"/>
   <xsd:complexType name="Model">
      <xsd:sequence>
         <xsd:element ref="ModelID"/>
         <xsd:element minOccurs="0" ref="VersionID"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="LikelihoodRating" type="enumConfidenceRating"/>
   <xsd:complexType name="ModelVersion">
      <xsd:sequence>
         <xsd:element name="VersionID" type="xsd:string"/>
         <xsd:element ref="ReleaseDate" minOccurs="1" maxOccurs="1"/>
         <xsd:element minOccurs="0" ref="Description"/>
         <xsd:element minOccurs="0" ref="Caveats"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:complexType name="Versions">
      <xsd:sequence>
         <xsd:element name="ModelVersion" type="ModelVersion" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>


   <!-- ================================
      Add-ons Impex
     ================================ -->
   <xsd:element name="PropertyTableURL" type="xsd:anyURI"/>
   <xsd:element name="SimulationProduct" type="enumProduct"/>
   <xsd:element name="InputEntity" abstract="true"/>
   <xsd:element name="RegionParameter" substitutionGroup="InputEntity" type="RegionParameter"/>
   <xsd:complexType name="RegionParameter">
      <xsd:sequence>
         <xsd:element ref="SimulatedRegion"/>
         <xsd:element minOccurs="0" ref="Description"/>
         <xsd:element minOccurs="0" ref="Caveats"/>
         <xsd:element minOccurs="0" ref="Radius">
            <xsd:annotation>
               <xsd:documentation>Radius of the Region in the simulation.</xsd:documentation>
            </xsd:annotation>
         </xsd:element>
         <xsd:element minOccurs="0" ref="SubLongitude">
            <xsd:annotation>
               <xsd:documentation>SubLongitude of the Parent of the Region body, in the body's planetocentric frame: Sun for planets and objects in the solar wind, Parent planet for satellites.</xsd:documentation>
            </xsd:annotation>
         </xsd:element>
         <xsd:element minOccurs="0" ref="Period">
            <xsd:annotation>
               <xsd:documentation>Rotation period of the object referenced as Simulation Region.</xsd:documentation>
            </xsd:annotation>
         </xsd:element>
         <xsd:element minOccurs="0" ref="ObjectMass"/>
         <xsd:element minOccurs="0" ref="InputTableURL">
            <xsd:annotation>
               <xsd:documentation>Link to a VOTable containing the value of the fields varying with time. These VOTable must have a column with time (ISO  or Julian), defined by the correct ucd and xtype,  and columns for each time-varying field which names corresponding to that of the field.</xsd:documentation>
            </xsd:annotation>
         </xsd:element>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Property"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="Radius" type="InputValue"/>
   <xsd:element name="SubLongitude" type="InputValue"/>
   <xsd:element name="Period" type="InputValue"/>
   <xsd:element name="InputParameter" type="InputParameter" substitutionGroup="InputEntity"/>
   <xsd:complexType name="InputParameter">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A container of information regarding an input
	       parameter of the simulation run. The parameter
	       may contain many properties.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SimulatedRegion" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Qualifier"/>
         <xsd:element ref="ParameterQuantity"/>
         <xsd:element ref="Property" minOccurs="1" maxOccurs="unbounded"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="ParameterQuantity" type="ImpexLargeListQuantities"/>

   <xsd:element name="Property" type="Property"/>
   <xsd:complexType name="Property">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A container of information regarding a property
	       of an input parameter.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PropertyQuantity" minOccurs="1" maxOccurs="1"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Qualifier"/>
         <xsd:element ref="Units" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="UnitsConversion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PropertyLabel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PropertyValue" minOccurs="0" maxOccurs="1"/>
         <xsd:element minOccurs="0" ref="PropertyTableURL"/>
         <xsd:element ref="ValidMin" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValidMax" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PropertyModel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ModelURL" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="PropertyQuantity" type="ImpexLargeListQuantities"/>
   <xsd:simpleType name="ImpexLargeListQuantities">
      <xsd:union
         memberTypes="enumFieldQuantity enumParticleQuantity enumMeasurementType enumParticleType enumDirectionAngle enumMixedQuantity enumSpectralRange enumWaveQuantity enumWaveType enumInstrumentType enumProcCoefType enumProcessType enumProduct enumImpexQuantity enumSupportQuantity"
      />
   </xsd:simpleType>

   <xsd:simpleType name="enumImpexRegion">
      <xsd:annotation>
         <xsd:documentation>Same as Spase's enum Region: identifiers for areas of the physical worl which may be occupied or observed + some IMPEx Special Region keyword related to areas in the simulation "world"</xsd:documentation>
      </xsd:annotation>
      <xsd:union memberTypes="enumRegion enumImpexSpecialRegion"/>
   </xsd:simpleType>

   <xsd:element name="InputPopulation" type="InputPopulation" substitutionGroup="InputEntity"/>
   <xsd:complexType name="InputPopulation">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Parameters associated to a simulated specie
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Set" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ParameterKey" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SimulatedRegion" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Qualifier"/>
         <xsd:element ref="ParticleType"/>
         <xsd:element minOccurs="0" ref="ChemicalFormula"/>
         <xsd:element minOccurs="0" ref="AtomicNumber"/>
         <xsd:element ref="PopulationMassNumber" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PopulationChargeState" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PopulationDensity" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PopulationTemperature" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="PopulationFlowSpeed" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Distribution" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProductionRate" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="TotalProductionRate" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="InputTableURL" minOccurs="0"/>
         <xsd:element ref="Profile" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ModelURL" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="InputField" type="InputField" substitutionGroup="InputEntity"/>
   <xsd:complexType name="InputField">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Parameters associated to a field imposed in the simulation
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Set" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ParameterKey" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SimulatedRegion" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="CoordinateSystem" minOccurs="0" maxOccurs="1"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Qualifier"/>
         <xsd:element ref="FieldQuantity" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="UnitsConversion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="InputLabel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="FieldValue" minOccurs="0" maxOccurs="1"/>
         <xsd:element minOccurs="0" ref="InputTableURL"/>
         <xsd:element ref="ValidMin" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValidMax" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="FieldModel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ModelURL" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:element name="InputTableURL" type="xsd:anyURI"/>

   <xsd:element name="InputProcess" type="InputProcess" substitutionGroup="InputEntity"/>
   <xsd:complexType name="InputProcess">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Parameters associated to a chemical process happening in the simulation
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Name" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Set" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ParameterKey" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SimulatedRegion" minOccurs="0" maxOccurs="unbounded"/>
         <xsd:element ref="ProcessType" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="UnitsConversion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProcessCoefficient" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProcessCoeffType" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ProcessModel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ModelURL" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="SimulationDomain" type="SimulationDomain"/>
   <xsd:complexType name="SimulationDomain">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Parameters associated to the simulation spatial domain.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="CoordinateSystem" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SpatialDimension" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="VelocityDimension" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="FieldDimension" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="UnitsConversion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="CoordinatesLabel" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValidMin" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="ValidMax" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="GridStructure" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="GridCellSize" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Symmetry" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="BoundaryConditions" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="BoundaryConditions" type="BoundaryConditions"/>
   <xsd:complexType name="BoundaryConditions">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Parameters associated to the simulation boundaries.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="ParticleBoundary" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="FieldBoundary" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="SimulationTime" type="SimulationTime"/>
   <xsd:complexType name="SimulationTime">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Parameters associated to the simulation time.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Description" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Duration" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="TimeStart" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="TimeStop" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="TimeStep" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="DiagnosisTimeStep" minOccurs="0"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="DiagnosisTimeStep" type="DiagnosisTimeStep"/>
   <xsd:complexType name="DiagnosisTimeStep">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Time at which a diagnosis is performed and quantity saved.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="SavedQuantity" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:attribute name="TimeStart" type="xsd:time"/>
      <xsd:attribute name="Duration" type="xsd:duration"/>
   </xsd:complexType>

   <xsd:element name="SavedQuantity" type="ImpexSavedQuantities">
      <xsd:annotation>
         <xsd:documentation>Quantitiesthat are saved during a given diagnosis.</xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:simpleType name="ImpexSavedQuantities">
      <xsd:union
         memberTypes="enumFieldQuantity enumParticleQuantity enumMixedQuantity enumWaveQuantity enumProduct"
      />
   </xsd:simpleType>


   <xsd:element name="ParticleBoundary" type="ElementBoundary"/>
   <xsd:element name="FieldBoundary" type="ElementBoundary"/>

   <xsd:complexType name="ElementBoundary">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Parameters associated to the simulation Boundaries.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Caveats" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="FrontWall" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="BackWall" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="SideWall" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="Obstacle" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="SpatialDescription" type="SpatialDescription"/>
   <xsd:complexType name="SpatialDescription">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the spatial extent over which
               the measurement was taken.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="Dimension" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="CoordinateSystem" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="Units" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="UnitsConversion" minOccurs="0" maxOccurs="1"/>
         <xsd:element ref="CoordinatesLabel" minOccurs="0" maxOccurs="1"/>
         <xsd:choice>
            <xsd:group ref="CutsDescription"/>
            <xsd:group ref="CubesDescription"/>
         </xsd:choice>
         <xsd:element ref="Step" minOccurs="0" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:complexType>
   <xsd:group name="CutsDescription">
      <xsd:annotation>
         <xsd:documentation>Substitution group to use with 3D simulation products</xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element ref="PlaneNormalVector" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="PlanePoint"/>
      </xsd:sequence>
   </xsd:group>
   <xsd:group name="CubesDescription">
      <xsd:sequence>
         <xsd:element ref="RegionBegin" minOccurs="1" maxOccurs="1"/>
         <xsd:element ref="RegionEnd" minOccurs="1" maxOccurs="1"/>
      </xsd:sequence>
   </xsd:group>
   <xsd:element name="PlanePoint" type="PlanePoint"/>

   <xsd:simpleType name="PlanePoint">
      <xsd:annotation>
         <xsd:documentation>A string list of the coordinate of a point in the plane.
</xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="FloatSequence"/>
   </xsd:simpleType>
   <xsd:element name="PlaneNormalVector" type="PlaneNormalVector">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">A string list of the component in each dimension of the vector normal to a plane.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:simpleType name="PlaneNormalVector">
      <xsd:annotation>
         <xsd:documentation>A string list of the component in each dimension of the vector normal to a plane.
</xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="FloatSequence"/>
   </xsd:simpleType>
   <xsd:element name="InputLabel" type="StringSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A string list of the labels of each dimension of the input parameter.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="CoordinatesLabel" type="StringSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A string list of the labels of each dimension of the spatial domain.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="GridCellSize" type="FloatSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A string list of the cell sizes in each dimension.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="TimeStart" type="xsd:time">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Time at which the coverage by the element start.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="TimeStop" type="xsd:time">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Time at which the coverage by the element stop.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="TimeStep" type="xsd:duration">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Time Step.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>

   <xsd:simpleType name="StringSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A list of string values.
         </xsd:documentation>
      </xsd:annotation>
      <xsd:list itemType="xsd:string"/>
   </xsd:simpleType>

   <xsd:simpleType name="FloatSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A list of real values.
         </xsd:documentation>
      </xsd:annotation>
      <xsd:list itemType="xsd:float"/>
   </xsd:simpleType>

   <xsd:element name="CodeLanguage" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Language in which a numerical code is written.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ModelID" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A string defining the ID of the model.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>

   <xsd:element name="Distribution" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Velocity distribution of the particles
            in a population.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Profile" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Density profile of the particles
            in a population.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="FieldModel" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Field model imposed in the simulation run.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProcessCoefficient" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Coefficient associated to a chemical process.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="SpatialDimension" type="xsd:integer">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Number of spatial dimensions in the simulation
            domain.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="VelocityDimension" type="xsd:integer">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Number of velocity dimensions in the simulation
            domain.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="FieldDimension" type="xsd:integer">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Number of field dimensions in the simulation
            domain.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="GridStructure" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Structure of the simulation grid.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Duration" type="xsd:duration">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Duration of the simulation.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Step" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation>Spatial step between two elements of the diagnosis.</xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="FrontWall" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Front wall of the simulation domain by
            which the plasma flow may be injected.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="BackWall" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Back wall of the simulation domain by
            which the plasma flow may exit the simulation.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="SideWall" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Side walls of the simulation domain.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Obstacle" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Obstacle in the simulation domain.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PropertyValue" type="StringSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A string list of the values of the property.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PropertyLabel" type="StringSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A string list of the labels of each dimension of the property.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PropertyModel" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Model used to define a property.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProcessModel" type="xsd:string">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Model used to describe a chemical process.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ModelURL" type="xsd:anyURI">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Url pointing toward the description of
            a model used in the definition of a
            property or an input.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>

   <xsd:element name="Dimension" type="xsd:integer"/>
   <xsd:element name="RegionBegin" type="FloatSequence"/>
   <xsd:element name="RegionEnd" type="FloatSequence"/>

   <xsd:element name="ObjectMass" type="InputValue">
      <xsd:annotation>
         <xsd:documentation>Mass of an object referenced as a simulated region.</xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PopulationMassNumber" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">            The total number of protons and neutrons (together
            known as nucleons) in an atomic nucleus.
</xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PopulationChargeState" type="xsd:double">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Charge of a particle in a population,
            in units of the charge of a proton. Charge
            state of a bare proton = 1.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PopulationDensity" type="InputValue">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            The number of particles per unit volume.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PopulationTemperature" type="InputValue">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A measure of the kinetic energy of random
            motion with respect to the average. Temperature
            is properly defined only for an equilibrium
            particle distribution (Maxwellian distribution).
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="PopulationFlowSpeed" type="InputValue">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            The rate at which particles or energy is passing
            through a unit area in a unit time.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProductionRate" type="InputValue"/>
   <xsd:element name="TotalProductionRate" type="InputValue"/>
   <xsd:element name="SimulationType" type="enumSimulationType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A characterization of the numerical scheme used in the simulation
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>

   <xsd:element name="ProcessType" type="enumProcessType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Type of chemical process.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="ProcessCoeffType" type="enumProcCoefType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
		Whether the simulation results are obtained from a stationnary 
		solution or are dynamically computed.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>

   <xsd:element name="TemporalDependence" type="enumYN" default="No">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
		Whether the simulation results are obtained from a stationnary 
		solution or are dynamically computed.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:element name="Symmetry" type="enumSymmetry">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Symmetry of the simulation domain.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>

   <xsd:simpleType name="enumProcessType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
		Type of Chemical Process
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="ChargeExchange">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
				Chemical process involving a charge
				transfer from an ion (which becomes neutral)
				to a neutral (which becomes ionized).
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="ElectronImpact">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Chemical process by which a neutral is 
			    ionized thanks to the energy from the
			    impact of an electron.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PhotoIonization">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Chemical process by which a neutral is 
			    ionized thanks to the energy from a photon.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="DissociativeRecombination">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Chemical process by which an ion is neutralized
			    by capturing an electron, and splits in two new
			    neutral species.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <xsd:simpleType name="enumProcCoefType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
		    Designation of the Process Coefficient type.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="CrossSection">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Cross section of the reaction, when the reaction 
			    implies the collision of two particles.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Frequency">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Reaction frequency: number of reaction per unit of time.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Rate">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Reaction rate: reaction production per unit of time.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Other">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Anything else.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <xsd:simpleType name="enumSymmetry">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
		List of possible spatial symmetries
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="None">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
				No Symmetry.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Axial">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Axial symmetry.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Plane">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Symmetry across a plane.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Central">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
		            Central Symmetry.
		         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>
   <xsd:simpleType name="enumYN">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
		Either Yes or No
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Yes"/>
         <xsd:enumeration value="No"/>
      </xsd:restriction>
   </xsd:simpleType>

   <!-- ==========================
Simulation Type

Identifiers for the characterization of the
numerical scheme used in the simulation.
========================== -->
   <xsd:simpleType name="enumSimulationType">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               Identifiers for the characterization of the
		numerical scheme used in the simulation.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="Hybrid">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A numerical scheme simulating ions as particles
	    and electrons as a fluid.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="MHD">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A numerical scheme simulating the plasma as a fluid.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="PIC">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A numerical scheme simulating ions and electrons
	    as macroparticles.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Test_Particle">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
            A numerical scheme simulating the motion of charged
	    particles in a prescribed field.
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
         <xsd:enumeration value="Paraboloid">
            <xsd:annotation>
               <xsd:documentation xml:lang="en">
         </xsd:documentation>
            </xsd:annotation>
         </xsd:enumeration>
      </xsd:restriction>
   </xsd:simpleType>

   <xsd:simpleType name="enumProduct">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
		Product type of the simulation results
            </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="3DCubes"/>
         <xsd:enumeration value="2DCuts"/>
         <xsd:enumeration value="TimeSeries"/>
         <xsd:enumeration value="SpatialSeries"/>
         <xsd:enumeration value="Lines"/>
         <xsd:enumeration value="Spectra"/>
      </xsd:restriction>
   </xsd:simpleType>

   <xsd:simpleType name="enumImpexQuantity">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Quantities for the description of IMPEx elements.
         </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string">
         <xsd:enumeration value="SolarUVFlux"/>
         <xsd:enumeration value="IMFClockAngle"/>
      </xsd:restriction>
   </xsd:simpleType>

   <xsd:element name="ChemicalFormula" type="ChemicalFormula">
      <xsd:annotation>
         <xsd:documentation>Chemical formula representing a population of particle.</xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:simpleType name="ChemicalFormula">
      <xsd:annotation>
         <xsd:documentation>Chemical formula representing a population of particle. Should only contain Chemical Symbols of th elements, numbers and Parenthesis: exemple O, O2, CO2,... Charge should be specifed elsewhere.

Note: use small case x, for undefined number of a given atom in a molecule (e.g. NOx), and W for water group if needed (H2O, OH, H3O,...).</xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string"/>
   </xsd:simpleType>
   <xsd:element name="Particle" substitutionGroup="ParameterEntity" type="Particle"/>
   <xsd:element name="PopulationID" type="PopulationID"/>
   <xsd:complexType name="Particle">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
               A description of the types of particles observed
               in the measurement. This includes both direct
               observations and inferred observations.
            </xsd:documentation>
      </xsd:annotation>
      <xsd:sequence>
         <xsd:element minOccurs="0" name="PopulationID" type="PopulationID"/>
         <xsd:element maxOccurs="unbounded" minOccurs="1" ref="ParticleType"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="Qualifier"/>
         <xsd:element maxOccurs="1" minOccurs="1" ref="ParticleQuantity"/>
         <xsd:element minOccurs="0" ref="ChemicalFormula"/>
         <xsd:element maxOccurs="unbounded" minOccurs="0" ref="AtomicNumber"/>
         <xsd:element minOccurs="0" ref="PopulationMassNumber" maxOccurs="unbounded"/>
         <xsd:element minOccurs="0" ref="PopulationChargeState" maxOccurs="unbounded"/>
         <xsd:element maxOccurs="1" minOccurs="0" ref="EnergyRange"/>
         <xsd:element maxOccurs="1" minOccurs="0" ref="AzimuthalAngleRange"/>
         <xsd:element maxOccurs="1" minOccurs="0" ref="PolarAngleRange"/>
      </xsd:sequence>
   </xsd:complexType>

   <xsd:element name="SimulatedInstrumentID" type="xsd:string"/>
   <xsd:element name="SimulatedRegion" type="enumImpexRegion">
      <xsd:annotation>
         <xsd:documentation>
               The portion of space simulated by the code
               at the time of a diagnosis. A region is
               distinguished by certain natural features
               or physical characteristics. It is the location
               of the observatory for in situ data, the location
               or region sensed by remote sensing observatories
               and the location-of-relevance for parameters
               that are derived from observational data.
            </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:complexType mixed="true" name="InputValue">
      <xsd:attribute name="Units" type="xsd:string">
         <xsd:annotation>
            <xsd:documentation xml:lang="en">
               A description of the standardized measurement
               increments in which a value is specified.
               The description is represented as a mathematical
               phrase. Units should be represented by widely
               accepted representation. For example, units
               should conform to the International System
               of Units (SI) which is maintained by BIPM
               (Bureau International des Poids et Mesures
               (see &lt;http://www.bipm.fr/&gt; ) when appropriate
               or use tokens like "Re" to represent units
               of the Radius of the Earth. Within a phrase
               the circumflex (^) is used to indicate a power,
               a star (*) is used to indicate multiplication
               and a slash (/) division. When symbols are
               not separated by a mathematical operator,
               multiplication is assumed. Symbols for base
               units can be found at: &lt;http://www.bipm.fr/en/si/si_brochure/chapter2/2-1/#symbols&gt;
               and those for common derived units can be
               found at: &lt;http://www.bipm.fr/en/si/derived_units/2-2-2.html&gt;
            </xsd:documentation>
         </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="UnitsConversion" type="xsd:string">
         <xsd:annotation>
            <xsd:documentation xml:lang="en">
               The multiplicative factor for converting a
               unit into International System of Units (SI)
               units. The factor is expressed in the form
               "number &gt; x", where "number" is a numerical
               value and "x" is the appropriate SI units.
               The basic SI units are Enumerated: m (meter),
               N (newton), kg (kilogram), Pa (pascal), s
               (second), Hz (hertz), A (ampere), V (volt),
               K (kelvin), W (watt), rad (radian), J (joule),
               sr (steradian), C (coulomb), T (tesla), ohm
               (ohm), mho (mho or seimens), H (henry), and
               F (farad). Two useful units which are not
               SI units are: degree (angle), and unitless
               (no units). An example is: "1.0E-5&gt;T" which
               converts the units, presumable nT, to tesla.
               Another example is: "1.0e+3&gt;m/s" which converts
               a velocity expressed in kilometers per second
               to meters per second.
            </xsd:documentation>
         </xsd:annotation>
      </xsd:attribute>
   </xsd:complexType>
   <xsd:element name="FieldValue" type="StringSequence">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            A string list of the values of the input parameter.
         </xsd:documentation>
      </xsd:annotation>
   </xsd:element>
   <xsd:simpleType name="PopulationID">
      <xsd:annotation>
         <xsd:documentation xml:lang="en">
            Unique Name of a particle population, for references.
         </xsd:documentation>
      </xsd:annotation>
      <xsd:restriction base="xsd:string"/>
   </xsd:simpleType>

</xsd:schema>
