An Orthophoto product, also Orthophotograph or Orthoimage, is an image that is geometrically processed (“Orthorectified”). It has the geometric qualities of a map: ground features are displayed in their true ground position because relief displacements caused by the camera and terrain have been removed. This enables direct measurements of distances, areas, angles and positions. Orthophotos are produced from an satellite image coupled with a Digital Elevation Model (DEM), a three-dimensional representation of the surface of a terrain. The final product, in the form of a raster or grid, may be used to create digitally-produced relief maps and other geographic information systems.