Research And Application On Quality For DEM Digital Surveying And Mapping Products

With the rapid development of digital information surveying and mapping technology, mapping and geoinformation data can be more quickly and efficiently acquired. As one of 4D digital products in national fundamental geographic information, it is widely used in many construction projects. At the same time, quality issues has increasingly become an urgent problem. Traditional quality inspection mode has many disadvantages, such as low working efficiency, many omissions, the check results are unstandardized and artificiality factor has great impact. The combination of computer technology and geographic information system technology on DEM digital surveying and mapping products quality research can accelerate the process of quality inspection informatization and improve the quality of DEM.Based on the understanding of DEM quality research of domestic and foreign scholars. Combined with DEM quality inspection module in "Quality Inspection Comprehensive Service System of Surveying and Mapping Achievements" project. According to the actual needs of inspection and acceptance. Using VS2010 C# and ArcEngine10.2 ComGIS technology to design and achieve the basic function of softwore:The quality inspection of elevation accuracy, taking the elevation value of the field measured point as the true value, in accordance with the bilinear interpolation method on the DEM to be checked for interpolation, using error model to evaluate the elevation accuracy; The quality inspection of edge-matching accuracy, achieving the consistency check of homologous point elevation in overlapping area between two adjacent DEM data; Research on the transformation of NSDTF-DEM format to Grid format, foundation mathematics of DEM, the correctness of filename, and some spatial visualization technology. Test shows that the program developed in this paper is running well and computed result can meet the requirements of a certain precision.