The Evaluation of the Internal Quality of Laser Scanning Strips Using the Interactive Orientation Method and Point Clouds

The quality of laser scanning point clouds has become a topical research issue. The quality has been determined by the sum of several error sources caused by various factors affecting accuracy. In this paper, it is proposed that overlapping laser strips are favourable for inspecting the quality of the point clouds. The internal quality of five almost completely overlapping strips from TopoSys Falcon was investigated using the interactive orientation method. The orientation was solved in several small test sites located in different parts of the complete overlapping area. Each relative orientation between two laser point clouds revealed possible height or planimetric shifts at the examination area. When this procedure was repeated in various locations within laser scanning strips, internal deviations of laser data strips became visible. The comparison was done relatively. Therefore, no ground control points were used. As a result, the repeatability in heights was excellent, whereas the planimetric repeatability, however, included more systematic and non-systematic errors. Interestingly, the flight direction was the main error source, and visible in the observed bias and random errors.