ABSTRACT
A common data source for terrain mapping and analysis is the digital elevation model (DEM). A DEM consists of a regular array of elevation points compiled from stereo aerial photographs, satellite images, radar data, and other data sources. For terrain mapping and analysis, a DEM is first converted to an elevation raster. The simple data structure of an elevation raster makes it relatively easy to perform computations that are necessary for deriving slope, aspect, and other topographic parameters.
