Forward looking sonar data collected along OFOBS profiles during POLARSTERN cruise PS101 (ARK-XXX/3)

The Ocean Floor Observation System (OFOS), used during Polarstern research cruise PS101 to the Langseth Ridge in the Central Arctic, was 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 OFOS during deployments. For PS101 the OFOS was upgraded to additionally mount an EdgeTech 2205 bathymetric side scan and a BlueView M900-130 forward looking sonar systems, to become the Ocean Floor Observation and Bathymetry System (OFOBS).