COMPARING THE APPROACHES FOR OBTAINING TIN FROM ONLY DEM POINTS
Yildiz Technical University, Geodesy and Photogrammetry Eng. Dept., Istanbul, Turkey
In some cases, it is necessary to obtain Triangular Irregular Network (TIN) as a Digital Terrain Model (DTM) from only Digital Elevation Model (DEM) points without any additional information or terrain features such as peaks, pits, passes or skeleton lines. The main purpose of this study is to determine the efficiency or the problems of such a TIN. Testing was done with several well-known commercial and scientific software packages. As a result, if the diagonals of the grids formed by the DEM points are uniformly created as triangle edges in triangulation, a regular TIN is obtained, but it may not approximate the earth’s surface very well, and the products of such a TIN, e.g. contours, are also not very satisfactory.