Fusing ROV-based photogrammetric underwater imagery with multibeam soundings for reconstructing wrecks in turbid waters
Observation and monitoring of wrecks are an integral part of the duties of hydrographic offices such as BSH. A common practice consists of first surveying wrecks using vessel-based multibeam echo sound-ing systems and subsequently having divers visually inspect them. In order to provide an objective pro-cedure and set a baseline for monitoring wrecks, unmanned underwater vehicles equipped with imag-ing systems can be used to inspect wrecks and other obstructions in more details. This paper presents a workflow for combining multibeam soundings and photogrammetric point clouds generated by a ROV-based camera system. Structure from motion and image enhancement are used to obtain a colour-coded point cloud, which is then fused and scaled with the multibeam soundings, resulting in data den-sification on wrecks. Finally, the feasibility of integrating this fused data to common hydrographic prac-tice is demonstrated.
ROV | underwater photogrammetry | multibeam echo sounder | point cloud fusion
