Shipboard ADCP current measurements (75 kHz) during RV SONNE cruise SO300/1

Current velocities of the upper water column along the cruise track of R/V Sonne cruise SO300/1 were collected by a vessel-mounted 75 kHz RDI Ocean Surveyor ADCP. The ADCP transducer was located at 6.0 m below the water line. The instrument was operated in narrowband mode (WM10) with a bin size of 8.00 m, a blanking distance of 8.00 m, and a total of 100 bins, covering the depth range between 22.0 m and 814.0 m. Heading, pitch and roll data from the ship's motion reference unit and the navigation data from the Global Positioning systems were used by the data acquisition software VmDAS internally to convert ADCP velocities into earth coordinates. The ship's velocity was calculated from position fixes obtained by the Global Positioning System (GPS). Accuracy of the ADCP velocities mainly depends on the quality of the position fixes and the ship's heading data. Further errors stem from a misalignment of the transducer with the ship's centerline. Data post-processing included water track calibration of the misalignment angle (-0.1371° +/- 0.5235°) and scale factor (0.9973 +/- 0.0078) of the Ocean Surveyor signal. The velocity data were averaged in time using an average interval of 120 s. Velocity quality flagging is based on different threshold criteria: Depth cells with ensemble-averaged percent-good values below 25% are marked as 'bad data'. Depth cells with velocities above 1.5 m/s are flagged as 'bad data'. Depth cells with a root-mean-square deviation between the measured ensemble-average velocity and a cell-wise running-mean velocity above 0.3 m/s are flagged as 'probably bad data'.

R/V Sonne号科考船SO300/1航次的航迹沿线上层水柱的当前流速，由船载75 kHz RDI Ocean Surveyor声学多普勒流速剖面仪（ADCP）采集。ADCP换能器位于水线以下6.0米处。仪器以窄带模式（WM10）运行，深度单元大小为8.00米，盲区距离为8.00米，共100个单元，覆盖22.0米至814.0米的深度范围。船载运动参考单元的航向、俯仰和横滚数据，以及全球定位系统（GPS）的导航数据，由数据采集软件VmDAS内部用于将ADCP流速转换为大地坐标系。船舶速度通过GPS获取的定位数据计算得出。ADCP流速的精度主要取决于定位数据的质量和船舶航向数据；进一步的误差源于换能器与船舶中心线的对准偏差。数据后处理包括对Ocean Surveyor信号的对准角度（-0.1371° +/- 0.5235°）和缩放因子（0.9973 +/- 0.0078）进行水迹校准。流速数据采用120秒的时间平均间隔进行平均。流速质量标记基于不同的阈值标准：集合平均有效百分比低于25%的深度单元标记为"坏数据"；流速超过1.5 m/s的深度单元标记为"坏数据"；测量的集合平均流速与逐单元滑动平均流速之间的均方根偏差超过0.3 m/s的深度单元标记为"可能坏数据"。