TopoComplexType, TopoComplex Maximal, sub- and super-complexes

Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. 147 The property elements gml:subComplex, gml:superComplex and gml:maximalComplex provide an encoding for relationships between topology complexes as described for gml:TopoComplex above.

13.5.3 topoPrimitiveMember

element name=topoPrimitiveMember type=gml:TopoPrimitivePropertyType complexType name=TopoPrimitivePropertyType sequence minOccurs=0 element ref=gml:AbstractTopoPrimitive sequence attributeGroup ref=gml:AssociationAttributeGroup attributeGroup ref=gml:OwnershipAttributeGroup complexType The gml:topoPrimitiveMember property element encodes for the relationship between a topology complex and a single topology primitive.

13.5.4 topoPrimitiveMembers

element name=topoPrimitiveMembers type=gml:TopoPrimitiveArrayAssociationType complexType name=TopoPrimitiveArrayAssociationType sequence minOccurs=0 maxOccurs=unbounded element ref=gml:AbstractTopoPrimitive sequence attributeGroup ref=gml:OwnershipAttributeGroup complexType The gml:topoPrimitiveMembers property element encodes the relationship between a topology complex and an arbitrary number of topology primitives. NOTE Because the property value can be multiple topological primitives, the elements representing the topology primitives are always encoded inline.

13.5.5 TopoComplexPropertyType, topoComplexProperty

complexType name=TopoComplexPropertyType sequence minOccurs=0 element ref=gml:TopoComplex sequence attributeGroup ref=gml:AssociationAttributeGroup complexType element name=topoComplexProperty type=gml:TopoComplexPropertyType The gml:topoComplexProperty property element encodes the relationship between a GML object and a topology complex. EXAMPLE This allows a feature collection to contain or reference a topology complex that contains topology objects referenced by members of the feature collection. 148 Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. 14 GML schema — Temporal information and dynamic features

14.1 General concepts

14.1.1 Overview

The GML temporal schemas include components for describing temporal geometry and topology, temporal reference systems, and the temporal characteristics of geographic data. The model underlying the representation constitutes a profile of the conceptual schema described in ISO 19108. The underlying spatiotemporal model strives to accommodate both feature-level and attribute-level time stamping; basic support for tracking moving objects is also included. Time is measured on two types of scale: interval and ordinal. An interval scale offers a basis for measuring duration, an ordinal scale provides information only about relative position in time. EXAMPLE A stratigraphic sequence or the geological time scale are examples of ordinal scales. Two other ISO standards are relevant to describing temporal objects: ISO 8601 describes encodings for time instants and time periods, as text strings with particular structure and punctuation; ISOIEC 11404 provides a detailed description of time intervals as part of a general discussion of language independent datatypes. The temporal schemas cover two interrelated topics and provide basic schema components for representing temporal instants and periods, temporal topology, and reference systems; more specialized schema components defines components used for dynamic features. Instances of temporal geometric types are used as values for the temporal properties of geographic features. NOTE The main temporal schema document is identified by the following location-independent name using URN syntax: urn:x-ogc:specification:gml:schema-xsd:temporal:3.2.1 The temporal topology schema document is identified by the following location-independent name using URN syntax: urn:x-ogc:specification:gml:schema-xsd:temporalTopology:3.2.1 The schema document for temporal reference systems is identified by the following location-independent name using URN syntax: urn:x-ogc:specification:gml:schema-xsd:temporalReferenceSystems:3.2.1 The dynamic feature schema document for representing time-varying properties of geographic features is identified by the following location-independent name using URN syntax: urn:x-ogc:specification:gml:schema-xsd:dynamicFeature:3.2.1 All schema documents are listed in Annex C.

14.1.2 Relationship with ISO 19108

The temporal geometry and topology components of the GML schema specified in this clause provide a conformant, partial implementation of the ISO 19108 temporal schema. The relationship is discussed in detail in D.2.5.