一种基于SWOT宽刈幅模拟数据的沿轨垂线偏差求解方法

2022年12月16日成功发射的SWOT是新一代宽刈幅测高卫星，预期可以提供全球海域及内陆水面的二维条带高度信息，有望解决传统一维观测值解算垂线偏差方向分量精度不一的问题。本文利用SWOT模拟数据联立多个方向求解沿轨垂线偏差，并根据模拟数据特点提出两种提升解算精度方案：一是选取联立观测值时适当增大距离，二是根据SWOT条带数据质量分别赋权。与EGM2008模型检核表明，SWOT模拟数据求得的垂线偏差南北向检核标准差为0.416 8角秒，东西向模型检核标准差为0.472 9角秒，解算质量优于其他方案，证明了改进方案的可行性，并利用“天宫二”号宽刈幅数据进行了方法验证，表明可应用于SWOT真实数据求解垂线偏差。

A method for solving along-track vertical deflection based on SWOT wide-swath simulated data

The SWOT was successfully launched on December 16, 2022, which is a new generation of wide-swath altimetry satellite. The SWOT is expected to provide two-dimensional strip hight informations of global sea area and inland water surface. It is expected to solve the problem of traditional one-dimensional observations, which is inconsistent accuracy in solving the directional component of the vertical deflection. In this paper, we adopted SWOT simulated data to solve along-track vertical deflection by jointing multi-directions, and proposed two upgrading schemes according to the characteristics of the simulated data: one is to increase the distance of joint observations appropriately, and the other is to assign weights according to the quality of SWOT strip data separately. The vertical deflection of the SWOT simulated data solved is checked with EGM2008 model, the standard deviation of the north component and east component are 0.416 8, 0.472 9 arcsec respectively. The solution quality is better than other schemes, it proves the feasibility of improved schemes. The method is also validated using Tiangong II wide-swath data. So it can be applied to SWOT real data to solve the vertical deflection.