Research And Realization On Partial Topological Algorithm For Vector Map Data

The incremental updating of vector map data is an effective method for rapid map data updating. As one of the key technique for the incremental updating of vector map data, the partial topological algorithm for vector map data can solve the efficiency problem caused by the topological information updating in course of data updating. This plays an important role in rapid map data updating. Based on the study of holistic topological algorithm for vector map data, this paper designed and realized the topological algorithm based on the change of region and the topological algorithm based on the topological editing, tried an experiment on the 1:250000 scale topographical map data, and put forward several improvement measures for the algorithms, as follorws:1. Introduced the importance of partial topological algorithm for the incremental updating of vector map data, and classified the existing partial topological algorithms;2. Described the related topological knowlege about vector map data, gave an all-around describiton to the existing holistic topological algorithm for vector map data updating, and described three main steps in the algorithm especially, including line feature intersecting, node matching, and area building.3. On the basis of holistic topological algorithm for vector map data, proposed a topological algorithm based on the change of region, and analyzed its difference and sameness to the holistic topological algrithm and the partial topological algrithm based on the state of changed features.4. Based on the analysis of the existing typical geodata model, designed a geodata model for topological editing. Proposed the concept of topological atom operations, and designed a series of topological atom operations for different topological elements. Designed the topological editing for different topological elements after the design of topological atom operations.5. Designed and realized an experimental system for the topological processing of vector map data. Analyzed the main affecting factors for the holistic toplogical algorithm and partial toplogical algorithm based on the change of range, and compared the performance of the two topological algorithms. Designed an incremental package for the topological data by adopting to xml file.