On data acquisition of moving objects via kinematic terrestrial laser scanning

Abstract. Terrestrial laser scanning (TLS) can be seen as an established method for geodetic data acquisition. Advantageous is its high achievable accuracy as well as its rapid, active and laminar sampling of the object space. However, problems occur if an object, the scanner itself or both are moving which is referred to as kinematic TLS (k-TLS). The cause of this issue is the sequential scanning principle of TLS which causes temporal offsets between measured points and hence describes a distinctive feature to photometric approaches. Due to this temporal shift movements of the scanner or an object lead to geometric falsification during data acquisition. If, however, one can determine current orientation and position of an object or the scanner at any point of time by applying additional sensor technology, geometrically correct and kinematic data acquisition can be derived. The contribution at hand presents a multi sensor system which applies a terrestrial laser scanner for acquisition of an object’s surface. In addition three tracking total stations are applied that monitor the object’s orientation and position within the coordinate system of the TLS. Influencing factors onto the geometric correction are the accuracy of the applied total stations for determination of six degrees of freedom (6dof) as well as the temporal synchronisation. At first an introduction into the problem domain is exemplified on a simple case. The system is then tested on a 2.5 m long ship model inside a research facility as well as outdoors on a 12 m long vessel. For the sake of assessment the results have been compared to statically acquired scans of the test objects, outside of the water respectively in position of rest, in order to derive reference models.