Representing and reasoning over spatio-temporal information in OWL 2.0

We propose SOWL, an ontology for representing and reasoning over spatio-temporal information in OWL. Building upon well established standards of the semantic web (OWL 2.0, SWRL) SOWL enables representation of static as well as of dynamic information, such as objects whose position evolves in time and space. The 4D fluents mechanism forms the basis of the proposed ontology representation in SOWL. Both RCC-8 topologic relations and cone shaped directional relations are supported and integrated in SOWL. Representing both qualitative temporal and spatial information (i.e., information whose temporal or spatial extents are unknown such as "left-of", "above" for spatial and "before", "after" for temporal relations) in addition to quantitative information (i.e., where temporal and spatial information is defined precisely) is a distinctive feature of SOWL. Qualitative representations are very common in natural language expressions such in free text or speech and can be proven to be valuable in the Semantic Web. The SOWL spatio-temporal reasoner offers capabilities for inferring new relations over spatio-temporal information and is another distinctive feature of our approach. Building upon tractable sets of temporal and spatial relations the SOWL reasoner also enforces path consistency and retains soundness, completness and tractability over the supported sets of relations.