Graphic Clipping Arithmetic And Its Application In Land Survey Information Processing

In the process of the research of the GIS (Geographic Information System) and the current method of Land Survey in practice,we established Land Survey Updating System based on Vector Graphics and Graphic Clipping Technology and come up with the solution of several key problems in land survey updating process to realize automatic updating large quantities of GPS high precision data and original map data on GIS platform.The research contents are summarized as follows:1. Because of Weiler-Athertoon Arithmetic invalidation in special instance, the Concept of General In/Out Point and Advanced Arithmectic are introduced.2. Adopt technology of Outside Rectangle, Double Buffer and Douglas Peucker to display great deal of map data rapidly.3. Design Auto Updating Method based on Graphic Clipping Arithmetic.It can compute correct geometry data and update corresponding attribute information to guarantee correctness and synchronization which avoid error from manual edit attribute information.4. Design and realize the Land Survey Data Updating Software based on OGC Simple Feature Specificaion Spatial Data Model.