The Surface Water and Ocean Topography (SWOT) altimeter mission can measure high-resolution wide-swath sea surface heights (SSHs) that may greatly improve the current accuracy and spatial resolution of marine gravity from nadir-looking altimeters. To investigate the potential of SWOT in recovering high-quality marine gravity and how SWOT observation errors should be treated to optimize the accuracy of gravity anomaly from SWOT observations, we create high-wavenumber SSH components from multi-beam depths in the northern South China Sea (SCS) and simulate SWOT SSH errors. To cross-validate gravity signals and avoid gravity errors from SWOT, we use two computational methods (inverse Vening-Meinesz formula, IVM and inverse Stokes' integral, ISM) and recommend separate optimal data processing strategies when using geoid gradients (GGs) and geoid heights (GHs) for gravity recovery. The use of GGs (for IVM) effectively eliminates systematic errors in gravity derivation. If GHs (for ISM) are used in gravity recovery, the tilt in wide-swath SSHs should be removed before gravity computation, and the recovered gravity must be filtered (post-processed) to avoid artificial gravity signals due to the SSH errors. Our assessments using mgal-accuracy shipborne gravity anomalies in the northern SCS show that multiple-cycle SWOT observations can deliver high-quality marine gravity anomalies. IVM is more robust than ISM in resisting random and systematic errors in SWOT. Our processing strategies can be used for the gravity validation of SSHs from SWOT's fast-sampling and science phases.

地表水和海洋地形 (SWOT) 高度计任务可以测量高分辨率的宽幅海面高度 (SSH)，这可能会大大提高来自最低点高度计的海洋重力的当前精度和空间分辨率。为了研究 SWOT 在恢复高质量海洋重力方面的潜力以及如何处理 SWOT 观测误差以优化 SWOT 观测重力异常的准确性，我们从南海北部的多波束深度创建了高波数 SSH 分量(SCS) 并模拟 SWOT SSH 错误。为了交叉验证重力信号并避免 SWOT 的重力误差，我们使用了两种计算方法（逆维宁-迈因斯公式、IVM 和逆斯托克斯积分，ISM) 并在使用大地水准面梯度 (GG) 和大地水准面高度 (GHs) 进行重力恢复时推荐单独的最佳数据处理策略。GGs（用于IVM）的使用有效地消除了重力推导中的系统误差。如果在重力恢复中使用 GH（用于 ISM），则在重力计算之前应去除宽幅 SSH 中的倾斜，并且必须对恢复的重力进行过滤（后处理）以避免由于 SSH 错误而产生的人工重力信号。我们在南海北部使用百万精度船载重力异常进行的评估表明，多周期 SWOT 观测可以提供高质量的海洋重力异常。IVM 在抵抗 SWOT 中的随机和系统错误方面比 ISM 更健壮。我们的处理策略可用于 SWOT 快速采样和科学阶段的 SSH 重力验证。