ImageCRSPropertyType TemporalCRS timeCS Concrete coordinate reference systems .1 CompoundCRS

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12.3.3.35 temporalDatum

element name=temporalDatum type=gml:TemporalDatumPropertyType gml:temporalDatum is an association role to the temporal datum used by this CRS.

12.3.3.36 TemporalCRSPropertyType

complexType name=TemporalCRSPropertyType sequence minOccurs=0 element ref=gml:TemporalCRS sequence attributeGroup ref=gml:AssociationAttributeGroup complexType gml:TemporalCRSPropertyType is a property type for association roles to a temporal coordinate reference system, either referencing or containing the definition of that reference system.

12.4 Coordinate systems

12.4.1 Overview

The coordinate systems schema components can be divided into three logical parts, which define elements and types for XML encoding of the definitions of:  coordinate system axes;  abstract coordinate system;  multiple concrete types of spatial-temporal coordinate system. These schema components encode the Coordinate System packages of the UML Models of ISO 19111:2007, Clause 9, and D.3.9 of this International Standard. NOTE The coordinateSystems schema document includes the referenceSystems.xsd GML schema document. This schema is identified by the following location-independent name using URN syntax: urn:x-ogc:specification:gml:schema-xsd:coordinateSystems:3.2.1 12.4.2 Coordinate system axes 12.4.2.1 CoordinateSystemAxis element name=CoordinateSystemAxis type=gml:CoordinateSystemAxisType substitutionGroup=gml:Definition complexType name=CoordinateSystemAxisType complexContent extension base=gml:IdentifiedObjectType sequence element ref=gml:axisAbbrev element ref=gml:axisDirection element ref=gml:minimumValue minOccurs=0 element ref=gml:maximumValue minOccurs=0 element ref=gml:rangeMeaning minOccurs=0 sequence 110 Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. attribute name=uom type=gml:UomIdentifier use=required extension complexContent complexType gml:CoordinateSystemAxis is a definition of a coordinate system axis.

12.4.2.2 axisAbbrev

element name=axisAbbrev type=gml:CodeType gml:axisAbbrev is the abbreviation used for this coordinate system axis; this abbreviation is also used to identify the coordinates in the coordinate tuple. The codeSpace attribute may reference a source of more information on a set of standardized abbreviations, or on this abbreviation. EXAMPLE Typical a bbreviations are ―X‖ and ―Y‖.

12.4.2.3 axisDirection

element name=axisDirection type=gml:CodeWithAuthorityType ‖ gml:axisDirection is the direction of this coordinate system axis or in the case of Cartesian projected coordinates, the direction of this coordinate system axis at the origin. EXAMPLE Typical directions may be north or south, east or west, up or down. Within any set of coordinate system axes, only one of each pair of terms may be used. For Earth-fixed CRSs, this direction is often approximate and intended to provide a human interpretable meaning to the axis. When a geodetic datum is used, the precise directions of the axes may therefore vary slightly from this approximate direction. NOTE A gml:EngineeringCRS often requires specific descriptions of the directions of its coordinate system axes. The codeSpace attribute shall reference a source of information specifying the values and meanings of all the allowed string values for this property.

12.4.2.4 minimumValue, maximumValue, rangeMeaning

element name=minimumValue type=double element name=maximumValue type=double The gml:minimumValue and gml:maximumValue properties allow the specification of minimum and maximum value normally allowed for this axis, in the unit of measure for the axis. For a continuous angular axis such as longitude, the values wrap-around at this value. Also, values beyond this minimummaximum can be used for specified purposes, such as in a bounding box. A value of minus infinity shall be allowed for the gml:minimumValue element, a value of plus infinity for the gml:maximumValue element. If these elements are omitted, the value is unspecified. element name=rangeMeaning type=gml:CodeWithAuthorityType gml:rangeMeaning describes the meaning of axis value range specified by gml:minimumValue and gml:maximumValue. This element shall be omitted when both gml:minimumValue and gml:maximumValue are omitted. This element should be included when gml:minimumValue andor gml:maximumValue are included. If this element is omitted when the gml:minimumValue andor gml:maximumValue are included, the