The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) satellite uses a synchronized multi-beam photon-counting method to collect data from three pairs of synchronous ground tracks. The sampling rate along the ground tracks is designed to be ~0.7 m, much smaller than that used in conventional radar altimeters. Hence, it is reasonable to expect an improvement in marine gravity recovery over coastal zones using ICESat-2 data. ICESat-2 provides valid sea surface height (SSH) measurements and a standard data product (ATL12) over ocean areas. This led us to consider the possibility of investigating its ability to calculate the deflection of vertical (DOV) and marine gravity anomalies. We processed ATL12 data about 22 months over the South China Sea (0°–23°N, 103°–120°E) and verified the ability of ICESat-2 SSH measurements to be used in calculating directional components of DOV. The results show that the ICESat-2 SSH data have a similar centimeter-magnitude accuracy level as data from the Jason-2 satellite. Furthermore, the accuracy of cross-track deflection of vertical (CTDOV) calculations between non-identical side beams is lower. For along-track points, the difference in accuracy between the solution of the prime component and the meridional component is significantly reduced, the prime component accuracy is significantly better than the directional components of the gridded deflection of vertical (GDOV), although the enhancement is weak for the meridional component. We also implemented the inversion of the ICESat-2 single mission based on the inverse Vening Meinesz formula, and verified the capability of ICESat-2 gravity field detection using shipborne gravity measurements and XGM2019 gravity field model, and found that the accuracy is 1.35 mGal and 2.47 mGal, respectively. ICESat-2 deserves the attention of the altimetry community, and its advantages are expected to make it an alternative data source for multi-mission fusion inversion of the ocean gravity field in the future.

中文翻译：

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根据ICESat-2数据计算南海垂直偏转和重力异常

冰，云和陆地高空卫星2（ICESat-2）卫星使用同步多光束光子计数方法从三对同步地面轨道中收集数据。沿地面轨迹的采样率设计为〜0.7 m，比常规雷达高度计中使用的采样率小得多。因此，使用ICESat-2数据预期沿海地区海洋重力恢复将有所改善是合理的。ICESat-2可提供有效的海平面高度（SSH）测量结果和整个海洋区域的标准数据产品（ATL12）。这使我们考虑研究其计算垂直（DOV）挠度和海洋重力异常的能力的可能性。我们处理了南海（0°–23°N，103°–120°E），并验证了ICESat-2 SSH测量可用于计算DOV方向分量的能力。结果表明，ICESat-2 SSH数据具有与Jason-2卫星数据相似的厘米级精度。此外，不同侧梁之间的垂直跨轨偏转（CTDOV）计算的准确性较低。对于沿轨点，主要分量和子午分量解的精度差异显着减小，主要分量精度明显优于垂直网格偏移（GDOV）的方向分量，尽管增强了子午线部分较弱。我们还根据反维宁·梅涅斯公式，对ICESat-2单任务进行了反演，并使用船载重力测量和XGM2019重力场模型验证了ICESat-2重力场检测的能力，发现精度分别为1.35 mGal和2.47 mGal。ICESat-2值得海事界关注，其优势有望使它成为未来海洋重力场多任务聚变反演的替代数据源。