Spatio-Temporal Predicates

Spatio-Temporal Predicates - IEEE TRANSACTIONS ON KNOWLEDGE...

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Spatio-Temporal Predicates Martin Erwig and Markus Schneider Abstract —This paper investigates temporal changes of topological relationships and thereby integrates two important research areas: First, two-dimensional topological relationships that have been investigated quite intensively and, second, the change of spatial information over time. We investigate spatio-temporal predicates, which describe developments of well-known spatial topological relationships. A framework is developed in which spatio-temporal predicates can be obtained by temporal aggregation of elementary spatial predicates and sequential composition. We compare our framework with two other possible approaches: one is based on the observation that spatio-temporal objects correspond to three-dimensional spatial objects for which existing topological predicates can be exploited. The other approach is to consider possible transitions between spatial configurations. These considerations help to identify a canonical set of spatio-temporal predicates. Index Terms —Time in geographic information, spatio-temporal data types, representation of spatio-temporal objects, changes of spatial predicates, developments of spatial objects. æ 1I NTRODUCTION T HE affinity of spatial and temporal phenomena has been recognized for a long time in literature. Both phenom- ena deal with “spaces” or “dimensions” of some kind and are thus closely related. The (regained) awareness of their deep relationships has led, both in spatial and in temporal data modeling, to an increased interest in integrating both directions into a common research branch called spatio- temporal data modeling and in constructing spatio-temporal data bases . Their underlying basic entities are called spatio- temporal objects and are ubiquitous in everyday life. Consider the flight of an airplane, the migration of whales, the raging of a storm, or the spreading of a fire region. Characteristic features of all these objects are that they are spatial entities changing over time and that these changes are continuous . Changes refer to the motion, shrinking, growing, shape transformation, splitting, merging, disappearing, or reappearing of spatio-temporal objects. In particular, the capability of incorporating continuous change of spatial objects over time belongs to the most challenging require- ments of spatio-temporal data modeling. In the meantime, some spatio-temporal data models (which will be described later) have already been proposed. Temporal changes of spatial objects induce modifications of their mutual topological relationships over time. For example, at one time, two spatio-temporal objects might be disjoint whereas, some time later, they might intersect. These modifications usually proceed continuously over time but can, of course, also happen in discrete steps.
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Spatio-Temporal Predicates - IEEE TRANSACTIONS ON KNOWLEDGE...

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