gml:TimeGeometricPrimitive acts as the head of a substitution group forgeometric temporal primitives. A temporal geometry shall be associated with a temporalreference system through the frame attribute that provides a URI reference that identifies adescription of the reference system. Following ISO 19108, the Gregorian calendar with UTC isthe default reference system, but others may also be used. The GPS calendar is analternative reference systems in common use. The two geometric primitives in the temporaldimension are the instant and the period. GML components are defined to support these asfollows.
Database handle for the object. It is of XML type ID, so is constrained to beunique in the XML document within which it occurs. An external identifier for the object inthe form of a URI may be constructed using standard XML and XPointer methods. This is doneby concatenating the URI for the document, a fragment separator, and the value of the idattribute.
Source
<element name="AbstractTimeGeometricPrimitive" type="gml:AbstractTimeGeometricPrimitiveType" abstract="true" substitutionGroup="gml:AbstractTimePrimitive"><annotation><documentation>gml:TimeGeometricPrimitive acts as the head of a substitution group for geometric temporal primitives. 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 GPS calendar is an alternative reference systems in common use. The two geometric primitives in the temporal dimension are the instant and the period. GML components are defined to support these as follows.</documentation></annotation></element>