基于TechDemoSat-1卫星的GPS反射信号海面高度反演

Sea surface height inversion of GPS reflected signal based on TechDemoSat-1 satellite

针对星载GPS反射信号(GPS-R)海面测高的误差问题,基于星载GPS-R实测数据进行星载海面测高模型和误差修正模型的研究,并验证其有效性。利用TechDemoSat-1(TDS-1)数据,使用时延多普勒图(DDM)海面高度反演技术,着重分析了星载GPS-R海面高度反演中的各类误差,并建立了相应的误差模型。对星载GPS-R海面高度反演模型进行优化,采用DTU15全球平均海面模型、DTU全球海潮模型验证反演精度。结果证明:优化后反演模型得到的全球海面高度反演结果的平均绝对误差(MAD)为6.05 m,精度提高了约29%,有效提高了海面高度反演的精度。研究成果对于推广星载GNSS反射信号(GNSS-R)的海面测高应用具有一定的意义。

The problems of using GPS-Reflectometry(GPS-R) measured data to establish satellite-borne sea surface height inversion model are studied and its validity is verified. The data of TechDemoSat-1(TDS-1) and the retrieval technique of Delay-Doppler Map(DDM) were used to analyze the errors in the retrieval of satellite-borne GPS-R sea surface height, and the error models were established. The satellite-borne GPS-R sea surface height inversion model was optimized. Meanwhile, the DTU15 global mean sea surface and sea tide model was adopted to verify the inversion accuracy. The results show that the Mean Absolute Deviation(MAD) of the global sea surface height inversion results obtained by the optimized inversion model is 6.05 meters, and the accuracy is improved by about 29%, effectively improving the accuracy of SST inversion. The research results have certain significance for promoting the application of spaceborne GNSS-Reflectometry(GNSS-R) in sea surface height inversion.