Integrative Model of Spatial Index and Multi-scale Representation

By building incremental spatial index in every display level,spatial index with multi-scale representation based on the graded display is combined;and the integration realizes multi-scale representation and extremely accelerates the accessing of spatial data at the same time.On the basis of the synthetical analysis of various types of indices' characteristics and their respective fitting range,a combined optimized strategy is put forward,which builds grid index for point objects,and builds optimized quad-tree index for line and area objects.The optimized quad-tree index designed by the authors avoids indexing features repeatedly and enhances the data access speed greatly.