A Research On The Key Technique Of DEM Data Extraction

The elevation data, which constructs the Digital Elevation Model——DEM, is very important. The topographic map contains a large amount of elevation information, and is an important source of DEM data. The problem of how to draw DEM data from the existing topographic map becomes the important research subject. In this thesis, the contour track method faced to DEM data, which is based on the thought that translates the contour information to DEM data, is put forward, and one effective inserted inside algorithm that relates on the contour interpolation generating DEM data is found.Three aspects are mainly studied in the thesis as follows:First, the contour track recognition method research. A contour track method facing DEM data drawing has been proposed, and the method can draw contour center line comparatively accurately.Second, the contour interpolates DEM data method research. The DEM data extraction algorithm based on the contour characteristic is proposed. This algorithm simulation the process of artificially interprets the elevation from topographic map, solved the problem of interpolation reference points selecting and increased the DEM data precision.Third, system design and realizationThe article has designed and realized a system of DEM data extraction and error analysis. This system integrated the algorithm which this article proposed with the correlation technology and the method ,and has completed entire process which from inputting the topographic map to producing the DEM data .