Vector Topographic Data Processing And Quality Control

The quality of spatial data is the life of every spatial databases. However, how to evaluate and control the quality of all sorts of data in the course of building DEM is a bottleneck problem of establishing various type databases and GIS. This dissertation has emphatically researched the correlative theory and technique about controlling the quality of contour vector data, and developed a suit of practical checking system combining with the actual needs. The main contents is listed as follows:1. According to the structure and characteristic of contour vector data, this paper has put forward some algorithm, which is very useful to check the contour data quality. A practical system of checking the contour data has been developed. It includes some function blocks, such as algorithm of checking bar codes, graphic roaming, zooming in, zooming out, editing and modifying, and the quality checking and evaluating.2. It has accomplished a direct interpolate method of building DEM and a means to construct TIN with contour lines. Plenty of experiments have been made during this work.3. The fractal dimension of contour data has been calculated with the fractal geometry theory. Consequently, the basis has been provided for the quantificational description of the contour' s complexity and the quantificational estimation of the workload.4. Gross errors in DEM are detected and corrected visually by applying the three-dimension visual technology.