Wanshan area has been chosen to be the specified field to calibrate and validate (Cal/Val) the HY-2 altimeter and its follow-on satellites. In March 2018, an experiment has been conducted to determine the sea surface height (SSH) under the HY-2A ground track (Pass No. 203). A GPS towing-body (GPS-TB) was designed to measure the SSH covering an area of about 6 km×28 km wide centered on the HY-2A altimeter satellite ground track. Three GPS reference stations, one tide gauge and a GPS buoy were placed in the research area, in order to process and resolve the kinematic solution and check the precision of the GPS-TB respectively. All the GPS data were calculated by the GAMIT/GLOBK software and TRACK module. The sea surface was determined by the GPS-TB solution and the tide gauge placed on Zhiwan Island. Then the sea surface of this area was interpolated by ArcGIS 10.2 with ordinary Kriging method. The results showed that the precision of the GPS-TB is about 1.10 cm compared with the tide gauge placed nearby, which has an equivalent precision with the GPS buoy. The interpolated sea surface has a bias of −1.5–4.0 cm with standard deviation of 0.2–2.4 cm compared with the checking line. The gradient of the measured sea surface is about 1.62 cm/km along the HY-2 orbit which shows a good agreement compared with the CLS11 mean sea surface (MSS). In the Cal/Val of satellites, the sea surface between the tide gauge/GPS buoy and the footprint of altimeter can be improved by this work.

中文翻译：

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万山地区使用GPS牵引器测量海面

选择万山地区作为指定区域，以校准和验证（Cal / Val）HY-2高度计及其后续卫星。2018年3月，进行了一项实验以确定HY-2A地面轨道（第203号合格证）下的海面高度（SSH）。设计了一个GPS牵引体（GPS-TB），以HY-2A高度计卫星地面轨道为中心，测量SSH覆盖约6 km×28 km宽的区域。在研究区内放置了三个GPS参考站，一个潮位计和一个GPS浮标，以分别处理和解决运动学问题并检查GPS-TB的精度。所有GPS数据均由GAMIT / GLOBK软件和TRACK模块计算得出。海面由GPS-TB解决方案和潮汐仪置于Zhi湾岛上确定。然后，ArcGIS 10.2使用普通的Kriging方法对该区域的海面进行插值。结果表明，与附近的潮汐仪相比，GPS-TB的精度约为1.10 cm，这与GPS浮标相当。与检查线相比，内插海面的偏差为-1.5-4.0 cm，标准偏差为0.2-2.4 cm。沿着HY-2轨道测得的海面坡度约为1.62 cm / km，与CLS11平均海面（MSS）相比，显示出良好的一致性。在卫星的Cal / Val中，通过这项工作可以改善潮汐计/ GPS浮标和高度计足迹之间的海面。具有与GPS浮标相当的精度。与检查线相比，内插海面的偏差为-1.5-4.0 cm，标准偏差为0.2-2.4 cm。沿着HY-2轨道测得的海面坡度约为1.62 cm / km，与CLS11平均海面（MSS）相比，显示出良好的一致性。在卫星的Cal / Val中，通过这项工作可以改善潮汐计/ GPS浮标和高度计足迹之间的海面。具有与GPS浮标相当的精度。与检查线相比，内插海面的偏差为-1.5-4.0 cm，标准偏差为0.2-2.4 cm。沿着HY-2轨道测得的海面坡度约为1.62 cm / km，与CLS11平均海面（MSS）相比，显示出良好的一致性。在卫星的Cal / Val中，通过这项工作可以改善潮汐计/ GPS浮标和高度计的覆盖面之间的海面。