Effective Implementation of Spatial Topological Operations Based on Anticlockwise Triangle

In this paper, we present a new approach to implement spatial topological operations for GIS data, which is based on anticlockwise triangle. Since the spatial topological operations of triangles are much easier to develop, so we first divide the vector- based GIS data into a set of non-intersected anticlockwise triangles, and then implement spatial topological operations for common GIS data through the sets of anticlockwise triangles. We first present a smallest set of 2-D spatial topological operations, and then the triangulation algorithm for a region is discussed, as well as the spatial topological operations of triangles, based on which the algorithms for spatial topological operations on points, lines, and regions are defined. Finally, the implementation of the spatial topological operations in a spatiotemporal database extending module is discussed. The querying experiments show that the anticlockwise-triangle-based approach works effectively.