Basic support for tracking moving objects and objects with changing state. Copyright (c) 2002-2005 OGC, All Rights Reserved. For conditions, see OGC Software Notice http://www.opengeospatial.org/about/?page=ipr A timeslice encapsulates the time-varying properties of a dynamic feature--it must be extended to represent a timestamped projection of a feature. The dataSource property describes how the temporal data was acquired. This type encapsulates various dynamic properties of moving objects (points, lines, regions). It is useful for dealing with features whose geometry or topology changes over time. The history relationship associates a feature with a sequence of TimeSlice instances. The track of a moving object is a sequence of specialized timeslices that indicate the status of the object. A dynamic feature may possess a history and/or a timestamp. A dynamic feature collection may possess a history and/or a timestamp.