DEM Map

http://www.ifp.illinois.edu/IDFL/results/resultsahuja.html

Above shown is a DEM map, short for Digital Elevation Model, this is a representation of a chosen area of Earth's surface to show the terrain in a detailed fashion. DEM's are closely related to DSM's (Digital Surface Model) and DTM's (Digital Terrain Model), whereas the DSM shows the surface without objects like plants or buildings. A DEM can be represented as a raster,  and are generated b using remote sensing techniques in relation with land surveying.