Normalised Digital Surface Model 50 NW

A normalised Digital Surface Model (nDOM) is a difference model consisting of a Digital Terrain Model (DGM) and a Digital Surface Model (DOM) and allows a determination of the relative object height above the terrain surface depicted as a plane. The district government of Cologne, Geobasis NRW, provides the product nDOM50 as part of its legal mandate for North Rhine-Westphalia and continues it continuously. To derive the nDOM50, a digital terrain model with a grid width of 0.5 m from laser scanning aflies as well as a (exclusively derived from summer flying, i.e. “certified”) image-based surface model with a floor resolution of 50 cm (bDOM50) is used. The normalised Digital Surface Model is used in particular in forestry and environmental management, e.g. for a further sensing-based tree species classification, or is used to derive land cover.