Digital Terrain Model

Digital Terrain Model (DTM) is a bare earth model that is generated using stereo pair of imageries. Such models become an integral part of topographic surveys. These models are also used to generate contour maps. Such models are the best depiction of slopes and aspects.

Digital Terrain Models (DTM) sometimes called Digital Elevation Models (DEM) is a topographic model of the bare Earth that can be manipulated by computer programs. The data files contain the elevation data of the terrain in a digital format that relates to a rectangular grid. Vegetation, buildings, and other cultural features are removed digitally - leaving just the underlying terrain.