Positioning and telemetry from ROV survey PS122/3_33-83 on 2020-03-28, survey 1

The horizontal position of the remotely operated vehicle (ROV) during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition between November 2019 and September 2020 was measured using an acoustic Long Base Line (LBL) positioning system (LinkQuest Pinpoint). The position was recorded in the SPOT.ON survey systems software (OceanModulesTM). The track was smoothed from initial acoustic fixes and cleaned for most obvious outliers. The position is in a floe-fixed, relative coordinate system (X, Y) with the origin (X=0 m, Y=0 m) at the ROV hole. A quality flag for the position is introduced based on the time to the closest fix with “1” indicating good positon (fix reached <= 3s), “2” medium position (fix reached > 3s & <= 5s), and “3” bad position (fix reached > 5s). Depending on the scientific aim, a position with quality flag “3” can still be useful. Vehicle depth was measured by the integrated pressure sensor and calibrated to 0 during pre-survey procedures, when the top side of the vehicle was at the same level as the water surface. Vehicle attitude (roll, pitch, heading) was measured with an onboard inertial measuring unit (IMU, Microstrain) with three axis accelerometer, magnetometer and gyroscope. Depth was measured by a pressure sensor (Keller A-21Y, Keller AG) included in the main electronics housing of the ROV.2019年11月至2020年9月期间，北极气候研究多学科漂流观测站（Multidisciplinary drifting Observatory for the Study of Arctic Climate, MOSAiC）科考航次中，遥控无人潜水器（Remotely Operated Vehicle, ROV）的水平位置通过长基线声学定位系统（Long Base Line, LBL，LinkQuest Pinpoint型号）完成测量。该位置数据通过SPOT.ON测量系统软件（OceanModules™）进行记录。原始声学定位结果经轨迹平滑处理，并剔除了绝大多数明显的异常值。位置数据采用浮冰固定相对坐标系（X, Y），坐标系原点（X=0 m, Y=0 m）设于潜水器开孔处。本次研究引入位置数据质量标记规则，以距最近有效定位的时长作为判定依据：标记“1”表示定位质量良好（定位响应时长≤3s），标记“2”表示定位质量中等（3s < 定位响应时长≤5s），标记“3”表示定位质量较差（定位响应时长>5s）。根据科学研究目标的不同，质量标记为“3”的位置数据仍具备使用价值。潜水器深度由集成压力传感器测得，并在预调查阶段完成校准——此时潜水器顶部与水面齐平，校准后深度基准设为0。潜水器的姿态（横滚、俯仰、航向）通过搭载的惯性测量单元（Inertial Measuring Unit, IMU，Microstrain型号）获取，该单元集成三轴加速度计、磁强计与陀螺仪。此外，潜水器深度还通过集成于主电子舱的压力传感器（Keller A-21Y型，Keller AG公司）进行测量。