Highly accurate documentation of accident scenes by laser scanners
In order to analyze the course of accidents in detail, officials in charge often need more information on the accident scene than, for instance, photos can provide you. In these cases, a complete documentation of the accident scene is of major importance for clearing up the accident. For that purpose, each detail, such as skid marks, road markings, fluid traces etc., can play an important role for the reconstruction of the course of the accident.
3D laser scanners are used for the quick and precise capturing of the accident scene. They scan the surroundings immediately point by point and, thus, survey the precise geometry of the accident scene. In that process, even details, which are invisible to the naked eye or whose importance is not even obvious for the investigation, are surveyed. The result of the three-dimensional survey is a point cloud. In order to scan everything and to avoid shadowing, scans are created from various positions. By means of reference points previously determined, the created point clouds can easily be merged in software. That way, a laser scanning project of the whole scanning area is created.
The high accuracy and the incredible detailing come along with a challenge to the analysis of data. Many solutions try to respond to the problem of depreciation or of scaling down the amount of data. This approach to the problem seems to be questionable since laser scanning is chosen because of the high detailing. Thus, why should you capture so many points and, afterwards, use only every fourth or tenth survey point?
Back to the task. The aim of the accident reconstruction was to document the geometry of the accident scene and the contained clues of the accident. Then, the result of this documentation is processed in accident simulation software, for instance PC-Crash.
PointCab for the documentation of accidents
With PointCab Forensics, Laserscanning Europe GmbH works on a special version of the popular software PointCab. “Our special algorithms allow a giant data reduction without disregarding a single measuring point“, said Laserscanning Europe's product manager Eike Thiele.
With only a few mouse clicks, PointCab creates the documentation of an accident based on the entire laser scanning project. Then, the ortho photos can be processed in the current software solutions of accidents experts.
3D point cloud of the accident scene
Accident reconstruction and simulation with PC-Crash
By means of the simulation tool PC-Crash, the precise accident investigation can be performed on the PC. Based on the terrain model, the motion sequences of vehicles can be reconstructed exactly and the course of the accident can be displayed in a 3D simulation. Then, the scenario can be regarded on the PC from various perspectives. Thus, it provides information on the visibility conditions, too. As a result, the statements of accident participants can be verified in detail.
Top view of an accident scene in PC-Crash
Measurement of distances and marking of important objects in PC-Crash
Due to the scan results and the simulations in PC-Crash, the course of accidents can be reconstructed in detail and possible reasons can be analyzed. The scan data and the results of the analysis are still available after months.
