Austrian construction giant Strabag has used a drone operating in beyond visual line of sight (BVLOS) mode to provide detailed aerial survey imagery for a project on the Autobahn 33 (A33) motorway in Germany.
Although drones are being increasingly used to speed up transportation and infrastructure survey work worldwide, they usually have to be within sight of their operators on the ground. However, in Germany, BVLOS is possible due to a unique relationship between telecommunications operator Deutsche Telekom and DFS (Deutsche Flugsicherung), the government-owned company in charge of German Air Traffic Control (ATC).
Drones are able to connect to the Unmanned Aircraft Systems Traffic Management (UTM) system that can locate, monitor and track drones connected over Deutsche Telekom’s LTE mobile cellular network, allowing safe flight management and control during BVLOS operations.
Strabag used US-German Unmanned Aerial Vehicle (UAV) manufacturer Microdrones and one of its specially equipped mdMapper1000DG quadcopter drones for the Autobahn corridor mapping project, as the company was able to meet the German requirements for conducting BVLOS in uncontrolled air space.
Microdrones worked with Strabag to fly the mdMapper1000DG, which was equipped with special transponders to make it visible to the German ATC system, and a 42.4MP Sony RX1R II high-definition camera. Once airborne, the mdMapper1000DG drone was tasked with creating a point cloud and orthophoto of a 7.5 mile-long (12km) stretch of the A33, with its LTE modem and a FLARM Collision Avoidance module used to assist with BVLOS flight.
Leading construction companies, such as Strabag, road operators and highways agencies, recognize that BVLOS drone use is very advantageous for corridor mapping, as it allows for longer flights that cover more area while capturing larger quantities of high-quality data. Strabag used the mdMapper1000DG on the A33 to provide closer inspection and visualization of the highway to find pavement imperfections, road wear and tear, and other potential safety hazards. Once all the data has been collected from the drone, it can be imported into popular survey software to create highly accurate visualizations such as orthomosaics or pointclouds.
Although it is highly complex in terms of its computer programming and processing, the unmanned aerial survey work is relatively cost-efficient and allows companies or agencies to analyze infrastructure remotely with the same kind of accuracy normally obtained through labor-intensive survey work, while removing the danger traditionally associated with ground-based assessment.