Terrestrial Scanning / Topography & Monitoring

Building Pit Survey - Austria 05.04.2008

TLS (Terrestrial Laser Scanning) is the most practicable workflow for this kind of application. The main factors are high speed data-acquisition in combination with high accuracy of the acquired data. The results can be delivered as written reports or as map-plots. The paper describes shortly the workflow of data-acquisition and points out the deliverable results. The field survey was carried out before starting excavation and after finishing excavation. Riegl’s RiSCANPRO software offers tools for automatic extraction of noisy data like vegetation, vehicles, etc. After removing these wrong measurements, the point-cloud, consisting of around one million points per data-set, is triangulated to get a closed surface-mesh of the data. Based on the 3D-surfaces contour-lines and profiles of any orientation are extracted automatically. The resulting 3D-polylines can be exported in dxf-format to AutoCAD. By defining an outline-polygon the excavation-volume is calculated. The results are shown in numbers as cut- and fill-volume, and can be also visualized by colorizing the 3D-surfaces according to their height-differences.