Mobile Lidar Mapping for Urban Data Capture

Terrestrial laser scanning is meanwhile frequently used to capture high quality 3D models of cultural heritage sites and historical buildings. However, the collection of dense point clouds can become very labor expensive, especially if larger areas like complete historic sections of a town have to be captured from multiple viewpoints. Such scenarios opt for vehicle based mobile mapping systems which allow for so-called kinematic terrestrial laser scanning. Within the paper the performance of this approach will be described on example of the “StreetMapper” system. There 3D data collection is realized by a combination of four 2D-laser scanners, which are mounted on a vehicle based, while a high performance GNSS/inertial navigation system provides the required georeferencing information. Within our investigations the accuracy of the measured 3D point cloud is determined based on reference values from an existing 3D city model. As it will be demonstrated, the achievable accuracy levels is better than 30mm in good GPS conditions and thus makes the system practical for many applications in urban mapping.