<?xml version="1.0" encoding="UTF-8"?>
<schema targetNamespace="http://www.opengis.net/gml" xmlns="http://www.w3.org/2001/XMLSchema" xmlns:sch="http://www.ascc.net/xml/schematron" xmlns:gml="http://www.opengis.net/gml" elementFormDefault="qualified" version="3.1.0">
	<annotation>
		<appinfo source="urn:opengis:specification:gml:schema-xsd:feature:v3.1.0"/>
		<documentation>
     		      GML Feature schema. 		      
     		      Copyright (c) 2001-2003 OGC, All Rights Reserved. 
	      </documentation>
	</annotation>
	<!-- ============================================================== -->
	<!-- ==================        includes and imports  ======================= -->
	<!-- ============================================================== -->
	<include schemaLocation="geometryBasic2d.xsd"/>
	<include schemaLocation="temporal.xsd"/>
	<!-- ============================================================== -->
	<element name="_Feature" type="gml:AbstractFeatureType" abstract="true" substitutionGroup="gml:_GML"/>
	<!-- =========================================================== -->
	<complexType name="AbstractFeatureType" abstract="true">
		<annotation>
			<documentation> An abstract feature provides a set of common properties, including id, metaDataProperty, name and description inherited from AbstractGMLType, plus boundedBy.    A concrete feature type must derive from this type and specify additional  properties in an application schema. A feature must possess an identifying attribute ('id' - 'fid' has been deprecated).  </documentation>
		</annotation>
		<complexContent>
			<extension base="gml:AbstractGMLType">
				<sequence>
					<element ref="gml:boundedBy" minOccurs="0"/>
					<element ref="gml:location" minOccurs="0">
						<annotation>
							<appinfo>deprecated</appinfo>
							<documentation>deprecated in GML version 3.1</documentation>
						</annotation>
					</element>
					<!-- additional properties must be specified in an application schema -->
				</sequence>
			</extension>
		</complexContent>
	</complexType>
	<!-- ============================================================== -->
	<!-- =========================================================== -->
	<element name="boundedBy" type="gml:BoundingShapeType"/>
	<!-- ====================================================================== -->
	<complexType name="BoundingShapeType">
		<annotation>
			<documentation>Bounding shape.</documentation>
		</annotation>
		<sequence>
			<choice>
				<element ref="gml:Envelope"/>
				<element ref="gml:Null"/>
			</choice>
		</sequence>
	</complexType>
	<!-- =========================================================== -->
	<element name="EnvelopeWithTimePeriod" type="gml:EnvelopeWithTimePeriodType" substitutionGroup="gml:Envelope"/>
	<!-- ====================================================================== -->
	<complexType name="EnvelopeWithTimePeriodType">
		<annotation>
			<documentation>Envelope that includes also a temporal extent.</documentation>
		</annotation>
		<complexContent>
			<extension base="gml:EnvelopeType">
				<sequence>
					<element ref="gml:timePosition" minOccurs="2" maxOccurs="2"/>
				</sequence>
				<attribute name="frame" type="anyURI" use="optional" default="#ISO-8601"/>
			</extension>
		</complexContent>
	</complexType>
	<!-- ====================================================================== -->
	<!-- ===== property for feature association ==== -->
	<element name="featureMember" type="gml:FeaturePropertyType"/>
	<element name="featureProperty" type="gml:FeaturePropertyType"/>
	<!-- ============================================================== -->
	<complexType name="FeaturePropertyType">
		<annotation>
			<documentation>Container for a feature - follow gml:AssociationType pattern.</documentation>
		</annotation>
		<sequence>
			<element ref="gml:_Feature" minOccurs="0"/>
		</sequence>
		<attributeGroup ref="gml:AssociationAttributeGroup"/>
	</complexType>
	<!-- ============================================================== -->
	<!-- ===== property for association of an array of features ===== -->
	<element name="featureMembers" type="gml:FeatureArrayPropertyType"/>
	<!-- =========================================================== -->
	<complexType name="FeatureArrayPropertyType">
		<annotation>
			<documentation>Container for features - follow gml:ArrayAssociationType pattern.</documentation>
		</annotation>
		<sequence>
			<element ref="gml:_Feature" minOccurs="0" maxOccurs="unbounded"/>
		</sequence>
	</complexType>
	<!-- ============================================================== -->
	<!-- =========================================================== -->
	<element name="_FeatureCollection" type="gml:AbstractFeatureCollectionType" abstract="true" substitutionGroup="gml:_Feature"/>
	<!-- ===========================================================   -->
	<complexType name="AbstractFeatureCollectionType" abstract="true">
		<annotation>
			<documentation> A feature collection contains zero or more features.  </documentation>
		</annotation>
		<complexContent>
			<extension base="gml:AbstractFeatureType">
				<sequence>
					<element ref="gml:featureMember" minOccurs="0" maxOccurs="unbounded"/>
					<element ref="gml:featureMembers" minOccurs="0"/>
				</sequence>
			</extension>
		</complexContent>
	</complexType>
	<!-- =========================================================== -->
	<element name="FeatureCollection" type="gml:FeatureCollectionType" substitutionGroup="gml:_Feature"/>
	<!-- =========================================================== -->
	<complexType name="FeatureCollectionType">
		<annotation>
			<documentation> Concrete generic feature collection.  </documentation>
		</annotation>
		<complexContent>
			<extension base="gml:AbstractFeatureCollectionType"/>
		</complexContent>
	</complexType>
	<!-- ============================================================== -->
	<!-- ============================================================== -->
	<element name="LocationKeyWord" type="gml:CodeType"/>
	<element name="LocationString" type="gml:StringOrRefType"/>
	<!-- =========================================================== -->
	<!-- ============= common aliases for geometry properties =============== -->
	<element name="centerOf" type="gml:PointPropertyType"/>
	<element name="position" type="gml:PointPropertyType"/>
	<element name="edgeOf" type="gml:CurvePropertyType"/>
	<element name="centerLineOf" type="gml:CurvePropertyType"/>
	<element name="extentOf" type="gml:SurfacePropertyType"/>
	<!-- =========================================================== -->
	<!-- ================= deprecated components  =========================== -->
	<complexType name="BoundedFeatureType" abstract="true">
		<annotation>
			<documentation> Makes boundedBy mandatory</documentation>
		</annotation>
		<complexContent>
			<restriction base="gml:AbstractFeatureType">
				<sequence>
					<group ref="gml:StandardObjectProperties"/>
					<element ref="gml:boundedBy"/>
					<element ref="gml:location" minOccurs="0">
						<annotation>
							<appinfo>deprecated</appinfo>
							<documentation>deprecated in GML version 3.1</documentation>
						</annotation>
					</element>
				</sequence>
			</restriction>
		</complexContent>
	</complexType>
	<!-- =========================================================== -->
	<element name="location" type="gml:LocationPropertyType">
		<annotation>
			<documentation>Deprecated in GML 3.1.0</documentation>
		</annotation>
	</element>
	<!-- ============================================================== -->
	<complexType name="LocationPropertyType">
		<annotation>
			<documentation>Convenience property for generalised location.  
      A representative location for plotting or analysis.  
      Often augmented by one or more additional geometry properties with more specific semantics.  </documentation>
			<documentation>Deprecated in GML 3.1.0</documentation>
		</annotation>
		<sequence>
			<choice>
				<element ref="gml:_Geometry"/>
				<element ref="gml:LocationKeyWord"/>
				<element ref="gml:LocationString"/>
				<element ref="gml:Null"/>
			</choice>
		</sequence>
		<attributeGroup ref="gml:AssociationAttributeGroup"/>
	</complexType>
	<!-- ============================================================== -->
	<element name="priorityLocation" type="gml:PriorityLocationPropertyType" substitutionGroup="gml:location">
		<annotation>
			<documentation>Deprecated in GML 3.1.0</documentation>
		</annotation>
	</element>
	<!-- ============================================================== -->
	<complexType name="PriorityLocationPropertyType">
		<annotation>
			<documentation>G-XML component</documentation>
			<documentation>Deprecated in GML 3.1.0</documentation>
		</annotation>
		<complexContent>
			<extension base="gml:LocationPropertyType">
				<attribute name="priority" type="string" use="optional"/>
			</extension>
		</complexContent>
	</complexType>
	<!-- ============================================================== -->
</schema>