Research And Implementation Of Spatial Topological Operations Based On Red And Blue Analysis

Computational geometry, which is based on discrete space, is the theoretical basis of Spatial Analysis Database System. It can not only ensure topological correctness of spatial analysis operations, but also have good efficiency. The conception Realms is a mathematical model which is used to describe the 2D spatial plane. It put forward an idea that all the spatial objects share a common aggregate of spatial elements such as points and segments and they are discrete and formatted with the criterion. Also a suit of rules used to sort the spatial elements is contained in the definition of Realms. With all these criterion and rules, we can acquire the topological relationship of spatial elements easily. And in computational geometry, there is a good way for us to implement spatial analysis operations. That is plane-sweep algorithm. But this algorithm is not aimed at spatial operations on layers of spatial objects. Therefore the author researches the character of red and blue layers of region objects, and designs a new sweep-line algorithm. This dissertation summarizes all kinds of topological relationships and spatial operations, and uses the conception realms to design the data structure of spatial region objects, and devises the red,blue planar graph algorithm, and makes use of red and blue sweep-line algorithm to implement the spatial topological analysis operations on layers of region objects. At the end, further works and improvements are presented.