The Research Of Vector Data Changes’ Detection Method Based On Triples

With China’s rapid economic and social development, the contradiction that thetimeliness of incremental vector data(as topographic map) is lagged far behind is breaking outday by day. State and local governments are increasing the vector feature database updatingand maintenance of technology and policy mechanisms, and the gradual establishment ofnational multi-scale vector elements of the database update system. For technical questions,including change detection, the primary database updates, customer database updates in threeareas. At this stage, change detection as one of the core issue is mainly used to automaticallyextract changes in surface features from remote sensing images and detect changes based oncombination of image and GIS, but change detection for vector elements still stay in thetraversal assay on a single class of elements, detection time-consuming, inefficient. View ofthis situation, this paper, based on the vector map data change detection method--triplesalgorithm, using graphical division (\), graphical by-division (/), graphical intersection (∩)data, constructs change detection model, and according to whether the three elements in theset of triples algorithm are empty and nonempty set, the change type of vector data (as point,line, area) change detection will be judged. Through total factor solutions from theperspective of vector graphics change detection problems, triples greatly reduce thecalculation amount, improve change detection efficiency. And the algorithm is validated byexperiment. The main contributions of the thesis are as follows:(1) It presents triples description model, from the viewpoint of the collection，it use theset of triples including graphical division (\), graphical by-division (/), graphical intersection(∩) through the old and the new data are overlaying and whether elements of triples are anddetermine the type of change, which greatly reduces the computational complexity, andsimplifies the process of vector elements change detection.(2) It uses triples algorithm combined with the geographic elements’ characteristics ofpoint, line, area and classify the changed elements which is detected. On this basis, the changedetection algorithm triples feasible experimental procedures.(3) It uses the road network between the Zaduo County and Yushu County as theexperimental data, and achieves results of the road network’ change detection by triplesalgorithm model, verifies the rationality of the algorithm.(4) The paper designs and achieved the prototype system of data change detection to thechanges of vector point, line and area, which uses the basic topographic vector date as anexample. The feasibility and efficiency of triples algorithm to detect changes have been proved in practical applications.