Metacat

<?xml version="1.0" encoding="UTF-8"?>

<schema targetNamespace="http://www.opengis.net/gml" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2001/XMLSchema" xmlns:gml="http://www.opengis.net/gml" elementFormDefault="qualified" attributeFormDefault="unqualified" version="3.2.0">

	<annotation>

		<appinfo source="urn:ogc:specification:gml:schema-xsd:direction:3.2.0">direction.xsd</appinfo>

		<documentation>See ISO/DIS 19136 Clause 18.

The direction schema components provide the GML Application Schema developer with a standard property element to describe direction, and associated objects that may be used to express orientation, direction, heading, bearing or other directional aspects of geographic features. </documentation>

	</annotation>

	<include schemaLocation="geometryBasic0d1d.xsd"/>

	<element name="direction" type="gml:DirectionPropertyType">

		<annotation>

			<documentation>The property gml:direction is intended as a pre-defined property expressing a direction to be assigned to features defined in a GML application schema.</documentation>

		</annotation>

	</element>

	<complexType name="DirectionPropertyType">

		<sequence minOccurs="0">

			<choice>

				<element name="DirectionVector" type="gml:DirectionVectorType"/>

				<element name="DirectionDescription" type="gml:DirectionDescriptionType"/>

				<element name="CompassPoint" type="gml:CompassPointEnumeration"/>

				<element name="DirectionKeyword" type="gml:CodeType"/>

				<element name="DirectionString" type="gml:StringOrRefType"/>

			</choice>

		</sequence>

		<attributeGroup ref="gml:OwnershipAttributeGroup"/>

		<attributeGroup ref="gml:AssociationAttributeGroup"/>

	</complexType>

	<complexType name="DirectionVectorType">

		<annotation>

			<documentation>Direction vectors are specified by providing components of a vector.</documentation>

		</annotation>

		<choice>

			<element ref="gml:vector"/>

			<sequence>

				<annotation>

					<appinfo>deprecated</appinfo>

				</annotation>

				<element name="horizontalAngle" type="gml:AngleType"/>

				<element name="verticalAngle" type="gml:AngleType"/>

			</sequence>

		</choice>

	</complexType>

	<complexType name="DirectionDescriptionType">

		<annotation>

			<documentation>direction descriptions are specified by a compass point code, a keyword, a textual description or a reference to a description.

A gml:compassPoint is specified by a simple enumeration.  	

In addition, thre elements to contain text-based descriptions of direction are provided.  

If the direction is specified using a term from a list, gml:keyword should be used, and the list indicated using the value of the codeSpace attribute. 

if the direction is decribed in prose, gml:direction or gml:reference should be used, allowing the value to be included inline or by reference.</documentation>

		</annotation>

		<choice>

			<element name="compassPoint" type="gml:CompassPointEnumeration"/>

			<element name="keyword" type="gml:CodeType"/>

			<element name="description" type="string"/>

			<element name="reference" type="gml:ReferenceType"/>

		</choice>

	</complexType>

	<simpleType name="CompassPointEnumeration">

		<annotation>

			<documentation>These directions are necessarily approximate, giving direction with a precision of 22.5°. It is thus generally unnecessary to specify the reference frame, though this may be detailed in the definition of a GML application language.</documentation>

		</annotation>

		<restriction base="string">

			<enumeration value="N"/>

			<enumeration value="NNE"/>

			<enumeration value="NE"/>

			<enumeration value="ENE"/>

			<enumeration value="E"/>

			<enumeration value="ESE"/>

			<enumeration value="SE"/>

			<enumeration value="SSE"/>

			<enumeration value="S"/>

			<enumeration value="SSW"/>

			<enumeration value="SW"/>

			<enumeration value="WSW"/>

			<enumeration value="W"/>

			<enumeration value="WNW"/>

			<enumeration value="NW"/>

			<enumeration value="NNW"/>

		</restriction>

	</simpleType>

</schema>