Sommaire de la publication

Sommaire de la publication

Marchand, P., A. Brisebois, Y. BĂ©dard & G. Edwards, 2004, Implementation and evaluation of a hypercube-based method for spatio-temporal exploration and analysis, International Society for Photogrammetry and Remote Sensing (ISPRS) Journal, Vol. 59, No. 1-2, pp. 6-20




In this article we test and evaluate the implementation of a dimension of spatio-temporal topological operators within a hypercube, a multidimensional database (MDDB) structure formed by the conjunction of several dimensions. Our goal is to permit adequate Spatio-Temporal Exploration and Analysis (STEA) in the context of Automatic Position Reporting System (APRS), the amateur radio system for position
report transmission. Mobile APRS stations are equipped with GPS navigation systems to provide real-time positioning reports. The multidimensional approach has already demonstrated a good potential for spatiotemporal exploration and analysis despite its lack of explicit spatial, temporal and spatio-temporal topological operators that are of key importance for spatio-temporal knowledge discovery. Our approach
implements spatio-temporal topological operators in multidimensional databases (MDDBs) through a hierarchy of topological operators representing spatial and temporal relationships between instances of objects, this hierarchy covers the three possible domains of spatio-temporal topological constrains e.g. spatial, temporal and spatio-temporal. At the root of the hierarchy users can make use of simple operators
such as “same place”, “same time” or “same time, same place” in their multidimensional query. As they drill down into the hierarchy more detailed topological operators are made available. This hierarchy is structured according to multiple levels of granularity based on cognitive models, generalized relationships and formal models of topological relationships. In this article we demonstrate that our generic approach allows adequate STEA by permitting spatio-temporal topological analysis within the multidimensional
approach. We also demonstrate that such an implementation offers query run times which permit to maintain a “train-of-thought” during exploration and analysis as they are compatible with Newell’s cognitive band (query runtime <10 seconds) (Newell, 1990).