This International Standard defines the standard concepts needed to describe the temporal
characteristics of geographic information as they are abstracted from the real world. Temporal
characteristics of geographic information include feature attributes, feature operations, feature
associations, and metadata elements that take a value in the temporal domain.
Temporal geometric and topological objects are used as values for the temporal characteristics of
features and data sets. TM_Object (Figure 7) is an abstract class that has two subclasses.
TM_Primitive is an abstract class that represents a non-decomposed element of geometry or topology
of time. There are two subclasses of TM_Primitive. A TM_GeometricPrimitive provides information
about temporal position. A TM_TopologicalPrimitive provides information about connectivity in time. A
TM_Complex is an aggregation of TM_Primitives.