Research On The Building And Application Of Digital Elevation Model In GIS

In the recent years, more and more attention has been attached to the research on the building and application of digital elevation, especially the terrain visualization.This paper demonstrated the principle and method of the digital elevation model construction on the basis of the regular grid and built the model. Three aspects of the digital elevation model applications were studied in detail:1 The drawing of contour line. The advanced method about tracing contour line was used to draw the contour line, which greatly improved the accuracy of the contour line drawing and solved the problem of contour point i.e. grid point.2 Terrain three-dimensional visualization based on OpenGL. An efficient data structure was exploited on the aspects of the terrain three-dimensional visualization and designed the inserting value method to make the display of the terrain three-dimensional visualization more vivid. Furthermore we made full use of the display listing table technique of OpenGL to reduce the occupation of CPU, and the display speed was enhanced.3 Spatial analysis of the digital terrain. Automatically drawingsection plane and the analysis of seeing each other between the random two points was realized.Combining the building model method mentioned above, connection of Visual C++ 6.0 with GIS software-MapInfo has been realized by adopting objective oriented designing and programming and OLE technology. Finally, we developed the DF3DTL program to materialize above three applications. This program has a certain practical value.