DEM Map

http://www.satimagingcorp.com/gallery/dem-sahara-tunisia-lg.html
DEM maps, also known as Digital Elevation Models, are usually 3-dimensional (3-D) representations of the terrain's surface. Maps are created using terrain elevation model data, and these maps usually feature the Earth's surface, a moon, or an asteroid. This map can be illustrated in two ways: raster (grids of equal size/shape squares), or in a network of irregular triangles. DEMs, while commonly built using remote sensing, can also be built using land surveying. DEMs are also required for many technical skills: these maps are used for anything from GIS/GPS, to base mapping and flight simulation.
The DEM map showed above is of the Sahara Desert, and was extracted from Stereo IKONOS Satellite Image data at 0.8m resolution.