Rapid Generation Of High Resolution Dem Based On The Constrained Data Field Triangulation Technology And Realization

With the widespread use of DEM, many aspects of DEM such as data acquisition methods, data storage and data processing speed have made some breakthroughs. But in the engineering applications of many areas, users bring up increasing demands for model precision and model efficiency. Rapidly producing technology of high-precision DEM has been a hotspot in the field of digital terrain modeling.The main content of paper is the research and realization of rapidly producing technology of high-precision DEM based on Delaunay triangulation of constrained data set, successfully resolving the bottleneck problems of large and high-precision DEM with rapidly producing in the engineering applications, and receiving a certification in actual applications. Specifically, the study covers the following aspects:(1) Based on studying the factors which influence the efficiency of traditional point-by-point-inserting algorithm, the algorithm about data structure, enveloping box, empty circum-circle test algorithm, the algorithm of fast finding the triangle which the point is in, the algorithm of fast inserting point and adjusting the topological relation are optimized. And an optimized algorithm is presented.(2) Based on the optimized point-by-point-inserting algorithm, a zoning-point-by-point-inserting algorithm is studied, which the efficiency and points are almost linear, successfully resolving the technology problems of large data D-TIN producing rapidly.(3) Based on the optimized point-by-point-inserting algorithm, an improved iterative algorithm on the basis of edge exchanging at two steps is studied, which the constrained line can be embedded, at the same time, it is extended for resolving the problems of constrained zone embedded. Based on the algorithm in the application, contour as constrained data embedded, landform character data embedded and work zone embedded are realizing, thus ensuring the generation of high-precision DEM.(4) Each part of the algorithms is based on the theoretical arguments, and standard procedure flow is designed. Referring to the flow charts, it can be easily converted into software achievement. (5) Based on the rapidly producing technology of high-precision DEM, the three-dimension system about highway locating is realized, which is simply introduced, proving the technology has the characteristic of better stabilization, higher model efficiency and wider adaptability.