Satellite Derived Digital Terrain and Perspective Models: An Aid to Teach Geologic Mapping

Digital Elevation Models (DEMs) are a good source of data where students can easily observe how the geology and the topography relate. Most geoscientific applications using georeferenced cartographic data need a good knowledge and vlsualization of the topography of the Earth's surface. For example, accurate mapping of geomorphological features is hardly feasible from a single image but it needs the three-Dimensional (3D) information to be added for a better interpretation of the two-Dimensional (2D) data.

This paper elucidates wlth examples, the potentia1 of satellite d erived DEM and DTM and illustrates how to visualize and extract geologic information from them. The aim here is to suggest a new teaching and to make students understand the geology of an area in a better way. Examples of DTM and perspective models of certain terrains of south lndia (the Andipatti-Usilampatti folded metasedimentary region and the structural basin in Palaniyarpuri) have been used in this paper to make geologists and students appreciate the utility of DEMs and DTMs. It has been demonstrated that for the undergraduate and postgraduate students of geology, a preliminary, virtual tour of the terrain to be mapped can be made possible using the DEM generated from satellite stereo images.