Natural Hazards and Earth System Science www.nat-hazards-earth-syst-sci.net 1561-8633 1684-9981 9 6 2009 10.5194/nhess-9-1921-2009 http://www.nat-hazards-earth-syst-sci.net/9/1921/2009/ http://www.nat-hazards-earth-syst-sci.net/9/1921/2009/nhess-9-1921-2009.html http://www.nat-hazards-earth-syst-sci.net/9/1921/2009/nhess-9-1921-2009.pdf 1921 1928 2009-11-19 Assessing the capability of terrestrial laser scanning for monitoring slow moving landslides A. Prokop alexander.prokop@boku.ac.at H. Panholzer Institute of Mountain Risk Engineering, Department of Civil Engineering and Natural Hazards, University of Natural Resources and Applied Life Sciences, Peter Jordanstrasse 82, 1190 Wien, Austria Digital elevation models (DEM) are widely used to determine characteristics of mass movement processes such as accumulation and deposition of material, volume estimates or the orientation of discontinuities. To create such DEMs point cloud data is provided by terrestrial laser scanning (TLS) and recently used for analysis of mass movements. Therefore the reliability of TLS data was investigated in a comparative study with tachymetry. The main focus was on the possibility of determining movement patterns of landslides &lt;100 mm. Therefore, several post processing steps are needed and the reliability of those were analyzed. The post processing steps that were investigated include: (1) The registration process is a crucial step considering long term TLS monitoring of an object and can be significantly improved using an iterative closest point (ICP) algorithm; (2) Filtering methods are necessary to create DEMs in order to separate favored laser points on the terrain surface (ground points) from topographically irrelevant points (non-ground-points). Therefore GIS tools were applied. 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