Data post-processing of Laser Scan Data for countrywide DTM production

The last years laserscanning has become a reliable and economic technology to build up high-class DTM. After doing tests to check the quality of laserscanning results and production method for their own purposes several German Surveying and Mapping Agencies have installed the new technology as new standard method for their official DTM production. Mandate, product line, production strategies and methods of the Surveying and Mapping Agency of Northrhine-Westfalia are described with special view to tests and use of the new technology. The solution for postprocessing of the laser data to check their completeness and quality of height level and terrain classification is then described in detail. Finally a short outlook is given to the next activities to improve economy of the post-processing process and the quality of its results.