TimeEdgePropertyType Temporal topology objects .1 Overview

162 Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved.

14.4.2 Basic temporal reference system, TimeReferenceSystem

A reference system is characterized in terms of its domain of validity: the spatial and temporal extent over which it is applicable. The basic GML element for temporal reference systems is gml:TimeReferenceSystem. Its content model extends gml:DefinitionType see 15.2.1 with one additional property, gml:domainOfValidity. It is implemented as follows: element name=TimeReferenceSystem type=gml:TimeReferenceSystemType substitutionGroup=gml:Definition gml:TimeReferenceSystem may be used in any position that a gml:Definition is valid. Its content model is defined as follows: complexType name=TimeReferenceSystemType complexContent extension base=gml:DefinitionType sequence element name=domainOfValidity type=string sequence extension complexContent complexType EXAMPLE This element might appear in an instance document as follows: gml:TimeReferenceSystem gml:id=JulianCalendar gml:description xlink:href=http:aa.usno.navy.mildatadocsJulianDate.html gml:nameJulian Calendargml:name gml:domainOfValidityWestern Europegml:domainOfValidity gml:TimeReferenceSystem

14.4.3 TimeCoordinateSystem

A temporal coordinate system shall be based on a continuous interval scale defined in terms of a single time interval. gml:TimeCoordinateSystem implements ISO 19108 TM_CoordinateSystem see D.2.5.9 and ISO 19108:2002, 5.3.3 with the exceptions specified below and is declared as follows: element name=TimeCoordinateSystem type=gml:TimeCoordinateSystemType substitutionGroup=gml:TimeReferenceSystem gml:TimeCoordinateSystem may be used in any position that a gml:TimeReferenceSystem is valid. Its content model is defined as follows: complexType name=TimeCoordinateSystemType complexContent extension base=gml:TimeReferenceSystemType sequence choice element name=originPosition type=gml:TimePositionType element name=origin type=gml:TimeInstantPropertyType choice element name=interval type=gml:TimeIntervalLengthType sequence extension complexContent complexType