DIN 18740-6:2014-12

Photogrammetry is a method to obtain and to process geometric and thematic information from images. A variety of sensors (e. g. cameras, radar, and laser) is applied to capture geo-related image data. This standard specifies the quality requirements for digital elevation models according to the objective of the series of standards DIN 18740. A digital elevation model is the interface between the earth's surface and the air. The elevation model is modelled by a representative three-dimensional point set (DEM). It can be distinguished between Digital Terrain Models (DTM) and Digital Surface Models (DSM). As for DTM the relief is recreated by a (erratic) raster or line-shaped arranged point set which is determined by position coordinates, height value and geomorphologic information. This point set describes the terrain surface in the requested accuracy and approximation. By contrast, the DSM additionally considers all visible static objects (e. g. buildings and vegetation) when modelling the interface to the air.