The project

STF Gruppe (www.stf-gruppe.de) is a German company active in a variety of engineering fields. It supports Deutsche Telekomn ation widein implementing its broadband expansion. As a partner, STF Gruppe provides support in the planning of fiber-opticnet works in businss parks, municipalities and new development areas – whether regular business such as FTTC/FTTH expansion or special projects such as TVUM (television and multimedia), transmission paths, MBfM (more broadband for me) and local area. One of the rural area documented was in the district of Sächsische Schweiz-Osterzgebirge, Saxony, Germany. The project required the survey of about 500 km of road. STF Gruppe selected Scanfly XT for its versatility, accuracy and for the compatibility with a high-resolution camera. The survey required about three days in the field, traveling at regular speed with no interferences to the traffic.

Workflow

Scanfly XT is typically installed in the survey vehicle in minutes. with the rooftop mount. The setup includes the NCTect iStar Pulsar +, a 60.5- megapixel panoramic camera, and a wheel sensor to ensure a smooth solution for the trajectory in areas with diminished GNSS conditions. The power supply is granted from the 12 V outlet of the vehicle itself with the dedicated battery pack. Batteries are also an option.In the field, the operator monitors the device status and activates the data acquisition in the regions of interest using a tablet, connected to the Scanfly XT via Wi-Fi. The WebApp just requires the device browser for full control of the operations.Later at the office, the data collected in the field are processed in two steps. Initially, the trajectory is evaluated with a PPK method, using the data from a local GNSS base station. Then, 3DT SmartProcessing Lidar generates the point clouds with RGB data and panoramic images, with a typical accuracy of less than 5 cm. The software also offers a dedicated export method for the STF Gruppe internal geographic system. The planning team will then locate the best position for the assets required for the broadband expansion.Mobile mapping systems based on Lidar ensure very flexible results, and an improvement in the workflow when compared to other survey methods. Furthermore, the digital twin can be used later for other engineering tasks.

Multi-platform

STF Gruppe also uses Scanfly XT for aerial surveys in combination with the DJI Matrice 300 RTK. The quick release allows for a quick switch between different survey vehicles. The main application is the collection of 3D information of mobile telephone towers, to detect the installed antennas or visible damages which require service.One of the last survey was performed to scan the Longinusturm, a 32-metre-high observation tower made of calcareous sandstone located in Nottuln, Germany. The tower was built at the end of 19th century and later adapted to host mobile telephone cells. With a flight of a few minutes, it was possible to collect 3D data to detect visible damages to the installed antennas. Nothing changes in the way Scanfly is controlled and in the way the data is processed later in an airborne scenario, making it easy to get the expected result for the operators.

The Scanfly advantages

Franz Wenkowitsch, SBE - Vermessungstechnik, Digitaler Zwilling of STF Gruppe says: «We were looking for a Lidar payload to cover our multiple survey needs. Scanfly XT provided us with the flexibility that we demanded. The panoramic images from the NcTech iStar Pulsar+ add value to the package. The fact that the Scanfly XT can be attached and detached quickly opens up the possibility to use it not only with one designated survey vehicle and still maintain high accuracy. After processing the data in Smart Processing Lidar the results can be exported in a suitable format to be integrated in our publishing platform.»