Forward facing acoustic camera seafloor sonar data from the southern Weddell Sea, collected during POLARSTERN cruise PS124

The Ocean Floor Observation and Bathymetry System (OFOBS), used during Polarstern research cruise PS124 to the southern Weddell Sea , a towed underwater camera system equipped with both a high-resolution photo-camera (iSiTEC, CANON EOS 5D Mark III) and a high-definition video-camera (iSiTEC, Sony FCB-H11). The cameras were mounted on a steel frame (150L x 92W x 105H cm), together with two strobe lights (iSiTEC UW-Blitz 250, TTL driven), three parallel laser pointers spaced with a distance of 50 cm used to estimate the size of seafloor structures, four LED lights, and a USBL positioning system (Posidonia) to track the position of the OFOBS during deployments. Additionally mounted on the platform was an EdgeTech 2205 bathymetric side scan and BlueView M900-130 forward facing acoustic camera sonar systems, to become the Ocean Floor Observation and Bathymetry System (OFOBS). Auxiliary sensors include an iXBlue PHINS 6000, and an AML Micro-X 6000 SV-Xchange sound velocity probe. An iXBlue DVL system was installed to augment the output of the PHINS 6000. The forward facing acoustic camera was particularly useful during the PS124 expedition as it revealed very clearly regions of the seafloor which had been used previously as nesting sites for ice fish. These abandoned nests were harder to distingusish from OFOBS camera images than from the acoustic forward facing camera data. Within this data set, all forward facing acoustic camera sonar data collected from the 20 deployments conducted during the cruise are presented