Seabed photographs taken along OFOS profile MSM77_35-4 during RV MARIA S. MERIAN cruise MSM77@en

During the RV MARIA S. MERIAN cruise MSM77 (2018-09-15 to 2018-10-13) to the long-term ecological research station HAUSGARTEN observatory in the Fram Strait the Ocean Floor Observation System (OFOS) was used to collect still images from various locations surveyed during the expedition. The OFOS consisted of a towed underwater camera system equipped with a high-resolution photo-camera (iSiTEC, CANON EOS 5D Mark III). The camera was mounted on a steel frame (140 L x 92 W x 135 H cm), together with two strobe lights, three 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. An automatic seafloor image was taken every 20 seconds to obtain 'TIMER' stills distributed at regular distances along each of the survey profiles. Additional 'HOTKEY' photos were triggered individually when interesting objects appeared in the live feed. Here, image data of OFOS deployment MSM77_35-4 is presented."MARIA S. MERIAN"号科考船第MSM77航次（2018年9月15日至2018年10月13日）赴弗拉姆海峡HAUSGARTEN长期生态观测站开展科考作业期间，科考团队采用海底观测系统（Ocean Floor Observation System, OFOS）采集了本次航次勘测区域内多站位的静态图像。该海底观测系统为拖曳式水下摄像系统，搭载一台高分辨率数码相机（型号为iSiTEC、CANON EOS 5D Mark III）。相机安装于尺寸为140（长）×92（宽）×135（高）厘米的钢制框架之上，同步搭载2台频闪补光灯、3台间距50厘米的激光指向仪（用于估算海底结构体的尺寸）、4台LED补光灯，以及一套超短基线（USBL）定位系统（Posidonia），用于跟踪布放作业期间OFOS的实时位置。系统每20秒自动拍摄一张海底图像，以获取沿每条勘测剖面等距分布的"TIMER"定时静态图像。当实时画面中出现目标观测物体时，可手动触发额外的"HOTKEY"抓拍照片。本数据集展示了OFOS布放作业MSM77_35-4对应的图像数据。