Grid Dem Quality Testing And Visualization Applications

Digital elevation model (DEM) is a kind of mathematics model of the earth's surface feature description, and is also one of the numerical 3D products of foundation geography infomation data. Information institute of photogrammetry and remote sensinng Yunnan (IIPRSY) is Yunnan Province's national instructional foundation geography data production base, there will have the massive of DEM digit products final achievement to submit to the Geograhpy infomation center of Yunnan (GICY) annually. But because DEM data lacks of intuitively external observeing pattern, so,quantity checking and accuracy valuation always are of a hard nut to its producer and checker.This paper through a software development example, with OpenGL has DEM data of the three models, through the establishment of mathematical models and related design efficient algorithms, in a three-dimensional model based on the realization of the Base Map of the slope, as-analysis , Rugged surface analysis, differential analysis, profile line generation, surface distance measureing, DOM and the DEM corrects applications. And to create the function to detection accuracy of DEM by using aerial triangulation encryption extended control point.OpenGL (Open Graphics Library) is a professional 3D programing interface, it is not merely a 3D graphics interface standard, or a new generation of 3D graphics industry standard, numerous software and hardware used by the manufacturers. Use it to the ground to achieve the visual model is a better choice.The author of this paper has worked in the fondation geogeaphy prodceing section IIPRSY over a long period of time. So can therefore set out from our reality to embark, and make a great deal of research at 3D digital geography data quality and its accuracy checking apperisal. The developing start at 2006 about digital geography produce checking software named "The YMCS checking system",with the instruction and help of my teachers, I has depened and developed one of DEM checking module,and make it perfect to use.Combineing the result, process and methods, I has finished the first draft of this thesis at February of 2008. the following paper achievement has been formed after the careful reorganization.