Digital Orthophotos, North Rhine-Westphalia, Germany

Orthophotos are high-resolution, distortion-free, true-to-scale images of the earth's surface. They are produced by photogrammetric methods with the use of orientation parameters and of a digital terrain model from aerial photographs that are available as vertical images. Digital orthophotos are georeferenced. They are available for the entire area of NRW and are renewed in a 3-year cycle. They are produced according to the product standard of the Federal State, which is based on the specifications of an AdV standard (AdV (german): Arbeitsgemeinschaft der Vermessungsverwaltungen der Länder) and have a ground resolution of 10cm/pixel. They are 4-band multispectral images with a band assignment of RGBI (Red-Green-Blue-Near Infrared).