<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="wcs">
    <xs:complexType>
      <xs:sequence>
        <xs:element minOccurs="0" ref="WCSDEPs"/>
        <xs:element minOccurs="0" ref="WCSAXES"/>
        <xs:element minOccurs="0" maxOccurs="unbounded" ref="CRPIXj"/>
        <xs:element minOccurs="0" maxOccurs="unbounded" ref="CRVALi"/>
        <xs:element minOccurs="0" maxOccurs="unbounded" ref="CDi_j"/>
        <xs:element minOccurs="0" ref="WCSNAME"/>
        <xs:element minOccurs="0" maxOccurs="unbounded" ref="CUNITi"/>
        <xs:element minOccurs="0" maxOccurs="unbounded" ref="CRDERi"/>
        <xs:element minOccurs="0" maxOccurs="unbounded" ref="CSYERi"/>
        <xs:element minOccurs="0" maxOccurs="unbounded" ref="CTYPEi"/>
        <xs:element minOccurs="0" maxOccurs="unbounded" ref="PVi_m"/>
        <xs:element minOccurs="0" ref="CelCooSys"/>
      </xs:sequence>
      <xs:attribute name="Owner" type="xs:IDREF" use="required"/>
      <xs:attribute name="version" type="xs:string" default=" "/>
    </xs:complexType>
  </xs:element>
  <xs:element name="WCSAXES">
    <xs:complexType>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="CRPIXj">
    <xs:complexType>
      <xs:attribute name="j" type="xs:string" use="required"/>
      <xs:attribute name="value" type="xs:string" default="0."/>
    </xs:complexType>
  </xs:element>
  <xs:element name="CRVALi">
    <xs:complexType>
      <xs:attribute name="i" type="xs:string" use="required"/>
      <xs:attribute name="value" type="xs:string" default="0."/>
    </xs:complexType>
  </xs:element>
  <xs:element name="CUNITi">
    <xs:complexType>
      <xs:attribute name="i" type="xs:string" use="required"/>
      <xs:attribute name="value" type="xs:string" default=" "/>
    </xs:complexType>
  </xs:element>
  <xs:element name="CDi_j">
    <xs:complexType>
      <xs:attribute name="i" type="xs:string" use="required"/>
      <xs:attribute name="j" type="xs:string" use="required"/>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="CRDERi">
    <xs:complexType>
      <xs:attribute name="i" type="xs:string" use="required"/>
      <xs:attribute name="value" type="xs:string" default="0."/>
    </xs:complexType>
  </xs:element>
  <xs:element name="CSYERi">
    <xs:complexType>
      <xs:attribute name="i" type="xs:string" use="required"/>
      <xs:attribute name="value" type="xs:string" default="0."/>
    </xs:complexType>
  </xs:element>
  <xs:element name="CTYPEi">
    <xs:complexType>
      <xs:attribute name="i" type="xs:string" use="required"/>
      <xs:attribute name="value" type="xs:string" default=" "/>
    </xs:complexType>
  </xs:element>
  <xs:element name="PVi_m">
    <xs:complexType>
      <xs:attribute name="i" type="xs:string" use="required"/>
      <xs:attribute name="m" type="xs:string" use="required"/>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="WCSNAME">
    <xs:complexType>
      <xs:attribute name="value" type="xs:string" use="required"/>
      <xs:attribute name="comment" type="xs:string"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="WCSDEPs">
    <xs:complexType>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="CelCooSys">
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="LONPOLE"/>
        <xs:element ref="LATPOLE"/>
        <xs:element minOccurs="0" ref="EQUINOX"/>
        <xs:element minOccurs="0" ref="MJD_OBS"/>
        <xs:element minOccurs="0" ref="RADESYS"/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
  <xs:element name="LONPOLE">
    <xs:complexType>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="LATPOLE">
    <xs:complexType>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="EQUINOX">
    <xs:complexType>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="MJD_OBS">
    <xs:complexType>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="RADESYS">
    <xs:complexType>
      <xs:attribute name="value" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
</xs:schema>
