RelatedTimeType AbstractTimeComplex Abstract temporal objects .1 AbstractTimeObject

Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. 151 A gml:AbstractTimeComplex may be used in any position that a gml:AbstractTimeObject is valid. Its content model is defined as follows: complexType name=AbstractTimeComplexType abstract=true complexContent extension base=gml:AbstractTimeObjectType complexContent complexType NOTE 1 This International Standard only specifies a temporal topology complex. A temporal geometric complex is not specified. NOTE 2 This International Standard does not distinguish a temporal linear graph from a temporal non-linear graph. 14.2.2 Temporal geometry 14.2.2.1 Introduction Temporal geometry is described in terms of time instants, periods, positions and lengths.

14.2.2.2 AbstractTimeGeometricPrimitive

gml:TimeGeometricPrimitive implements ISO 19108 TM_GeometricPrimitive see D.2.5.2 and ISO 19108:2002, 5.2.3 and acts as the head of a substitution group for geometric temporal primitives. It is declared as follows: element name=AbstractTimeGeometricPrimitive type=gml:AbstractTimeGeometricPrimitiveType abstract=true substitutionGroup=gml:AbstractTimePrimitive A gml:AbstractTimeGeometricPrimitive may be used in any position that a gml:AbstractTimePrimitive is valid. Its content model is defined as follows: complexType name=AbstractTimeGeometricPrimitiveType abstract=true complexContent extension base=gml:AbstractTimePrimitiveType attribute name=frame type=anyURI default=ISO-8601 extension complexContent complexType A temporal geometry shall be associated with a temporal reference system through the frame attribute that provides a URI reference that identifies a description of the reference system. Following ISO 19108, the Gregorian calendar with UTC is the default reference system, but others may also be used. The two geometric primitives in the temporal dimension are the instant and the period. GML components are defined to support these as follows.

14.2.2.3 TimeInstant

gml:TimeInstant implements ISO 19108 TM_Instant see D.2.5.2 and ISO 19108:2002, 5.2.3.2 and acts as a zero-dimensional geometric primitive that represents an identifiable position in time. It is declared as follows: element name=TimeInstant type=gml:TimeInstantType substitutionGroup=gml:AbstractTimeGeometricPrimitive 152 Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. A gml:TimeInstant may be used in any position that a gml:AbstractTimeGeometricPrimitive is valid. Its content model is defined as follows: complexType name=TimeInstantType final=all complexContent extension base=gml:AbstractTimeGeometricPrimitiveType sequence element ref=gml:timePosition sequence extension complexContent complexType EXAMPLE In an instance document, a gml:TimeInstant contains a gml:timePosition as follows: gml:TimeInstant gml:id=t11 gml:descriptionAbbys birthdaygml:description gml:timePosition2001-05-23gml:timePosition gml:TimeInstant

14.2.2.4 TimeInstantPropertyType

gml:TimeInstantPropertyType is a specialization of gml:TimePrimitivePropertyType that provides for associating a gml:TimeInstant with an object: complexType name=TimeInstantPropertyType sequence minOccurs=0 element ref=gml:TimeInstant sequence attributeGroup ref=gml:AssociationAttributeGroup attributeGroup ref=gml:OwnershipAttributeGroup complexType

14.2.2.5 TimePeriod

gml:TimePeriod implements ISO 19108 TM_Period see D.2.5.2 and ISO 19108:2002, 5.2.3.3 and acts as a one-dimensional geometric primitive that represents an identifiable extent in time. It is declared as follows: element name=TimePeriod type=gml:TimePeriodType substitutionGroup=gml:AbstractTimeGeometricPrimitive gml:TimePeriod may be used in any position that a gml:AbstractTimeGeometricPrimitive is valid. Its content model is defined as follows: complexType name=TimePeriodType complexContent extension base=gml:AbstractTimeGeometricPrimitiveType sequence choice element name=beginPosition type=gml:TimePositionType element name=begin type=gml:TimeInstantPropertyType choice choice element name=endPosition type=gml:TimePositionType element name=end type=gml:TimeInstantPropertyType choice group ref=gml:timeLength minOccurs=0 sequence