A rule system for heterogeneous spatial reasoning in geographic information system

In this article, we investigate the hybrid spatial reasoning problem in geographic information system, which can be formulated as a hybrid formalism, which combines two essential formalisms in qualitative spatial reasoning: topological formalism and cardinal direction formalism. Although much work has been done in developing composition tables for these formalisms, the previous research for integrating heterogeneous formalisms was not sufficient. Instead of using conventional composition tables, we investigate the interactions between topological and cardinal directional relations with the aid of rules that are used efficiently in many research fields such as content-based image retrieval. These rules are shown to be sound, i.e. the deductions are logically correct. Based on these rules, an improved constraint propagation algorithm is introduced to enforce the path consistency.