Surveying Frankfurts harbour
Increased efficiency through combined technologies
Since 2014, german TPI Vermessungs GmbH from Dreieich is using the Aibotix Aibot X6 UAV (unmanned aerial vehicle) from Leica Geosystems in addition to its GPS, GNSS, laser scanning and tachymeter products. The greatest advantage, however, is the possibility to combine all these different technologies from Leica Geosystems to get the most detailed result.
The Frankfurt Osthafen, a transhipment center for oil, coal, grain and gravel since 1912, required the combined use of multisensor combination to provide the most precise results. In addition to the creation of a digital terrain model (DGM) as well as the volume calculation of buildings with a hall of approx. 7,800 m² as well as an outside area of approx. 15,600 m², the entire range of the available technology was needed. The indoor-data was collected using the Leica Geosystems HDS 7000 laser scanner. Thanks to the very good reach of over 180 m, the data could be generated quickly so that the process could be completed within a short period of time.
The outside area were inspected with the Aibot X6 UAV in order to ensure that the operation on the ground remained largely undisturbed and on the other hand to use the strength of airborne photogrammetry with the Aibot X6 continuous moving of the data collecting hardware was not necessary because of the possibility to plan the flights in the office and then automatically perform them under observation of a trained UAV pilot. The overall terrain was subdivided into different sections and the accuracy of the data was determined. All parameters can be changed in the Aibotix AiProFlight software, to always adapt the settings to the respective project.
For this project the Leica Viva TS15 and the Leica Viva GS08 were used to measure the points for the geo-referencing of the UAV data. Through this preparation all of the 450 photos on the onboard GPS of the Aibot X6 could be prepared and georeferenced for postprocessing with an accuracy of 1 cm of floor resolution. The flights were carried out at a height of 60 m, the photographs were planned with an overlap of 70%, making it possible to create a highly accurate orthophoto. The use of the UAV makes it possible to use the full range of photogrammetry at a comparatively low cost. With just a few more steps in the software Agisoft PhotoScan, an intuitive 3D model could be created from the orthophotos.
With the help of Leica Cyclone a point cloud was generated and added to the data collected with the Leica laser scanners. The final combination and total volume accounting was carried out with Autodesk AutoCAD. Therefore the point clouds from the indoor and outdoor area were combined. The day-to-day business in the processing of the multisensor data can be significantly more efficient thanks to the good interaction of every Leica product. The use of an UAV can significantly reduce long-term processes in the field of external service when recording the data.
Within six hours, the volume calculation and the compilation of the DGM of the Frankfurter Osthafen were carried out of all the generated data. The evaluations were handed over to the client after two processing days. Such process times are only possible on the basis of an intelligent combination of different sensors for data acquisition as well as the correct software during the subsequent evaluation.