|M.Sc Student||Alon Lichtenstein|
|Subject||Accuracy Analysis of DTMs Combined with Breaklines|
|Department||Department of Civil and Environmental Engineering||Supervisor||Professor Emeritus Doytsher Yerach|
Digital Elevation Databases (DED) constitute a central component of the great boost to all mapping and GIS fields, as the variety of applications that are supported by it is practically infinite. A variety of sophisticated Technologies brought a huge availability of automatic elevation data. The surface data obtained applying these automatic techniques is not sufficiently reliable, and requires addition characteristic data such as break-lines. Merging break-lines and DTM is a part of a bigger challenge of modeling three-dimensional surfaces. An analysis is presented on the improvement in the accuracy of surface representation after applying different techniques for break-lines incorporation. Numerous experiments were carried out in different areas, based on very accurate measurements, which enabled profound analysis and conclusions. The research demonstrates a proven ability using sparse grids combined with break-lines for reliable and accurate modeling. Two appropriate techniques are proposed for merging break-lines with DTM. The first one, some how, extend the existing (commercial packages) technique, while the other one has been developed to combine DTM and break-lines in a different approach. The two proposed techniques represent two different approaches for DTM and break-lines incorporation, described in the theoretical review. One of the major conclusions of the research is that a combination between the two techniques, will, probably, yield the best resultant surface. Comparative reports of the proposed techniques as well as efficiency analysis comparing the cost-effectiveness of sparse grids merged with break-lines verses dense grids are presented. Some future research activities dealing with the challenging field of modeling elevation data are also proposed.