Benthic megalitter detection using unmanned surface vehicle (USV) and Automatic Target Detection: A case study in the Port of Thessaloniki, Thermaikos Gulf

In the port of Thessaloniki, Greece, benthic megalitter detection was achieved using an Unmanned Surface Vehicle (USV) equipped with a compact high resolution sidescan sonar (SSS) and a single beam echsosounder (SBES). The benthic megalitter survey was organized in two separate phases. Firstly, a systematic hydroacoustic survey using the SBES and SSS managed to outline and map all the acoustic anomalies. The second phase followed using the ROV hovered over these acoustic anomalies and the sites were identified on the video camera. An Automated Target Detection procedure, based on acoustic texture analysis and Independent Component Analysis (ICA), was applied for the automated detection of acoustic anomalies. The ground truth survey attested that the anomalies represent megalitter (metallic items, car tires, wires, e.t.c.). The developed procedure had promising results towards fast detection of the benthic megalitter in coastal areas.