Autonomous surveying of a section of the Ruhr: Field report on high-resolution bathymetry

Abstract The Düsseldorf district government commissioned the Fraunhofer Institute for Optronik, Systemtechnik, and Information Technology (IOSB) to conduct a bathymetric measurement of a six-km section of the Ruhr River by an autonomous surface vehicle (ASV). The ASV is based on the Otter Pro vehicle and is equipped with multibeam sonar, inertial sensors, RTK GNSS, LiDAR, and cameras. The ROS-based algorithm toolbox (ATB) from Fraunhofer IOSB provided the autonomy and multi-sensor fusion functionality such as navigation, mission planning, obstacle avoidance, data acquisition, and preprocessing. A fully georeferenced 3D model of the riverbed and partially of the bank structures was generated from the data of a four-day measurement campaign. The article elaborates on the technical characteristics of the platform, the sensor technology employed, the autonomy capabilities of the platform, the software components utilized, the encountered challenges, and the ensuing outcomes.