SDUST2021GRA: global marine gravity anomaly model recovered from Ka-band and Ku-band satellite altimeter data

Abstract. With the launch of altimetry satellites with different observation frequencies and survey missions, it is necessary to integrate multi-satellites altimeter data establish a new global marine gravity anomaly model. Based on Ka-band sea surface heights (SSHs) from SARAL/AltiKA Ku-band SSHs other (including HY-2A) in geodetic missions exact repeat model SDUST2021GRA 1? × grid derived. Gridded deflections vertical (DOV) are determined along-track geoid gradients by least squares collocation method, which noise variances obtained iteration method for mission SSH crossover discrepancies missions. recovered gridded DOVs inverse Vening Meinesz formula, analyzed comparing recognized models DTU17 SIO V30.1. Finally, accuracy SDUST2021GRA, DTU17, V30.1 assessed preprocessed shipborne anomalies. In conclusion, differences between small, indicating reliability SDUST2021GRA. The mainly concentrated ?5 5 mGal, accounts more than 95 % total number. Assessed gravity, 2.37 mGal globally, higher that (2.74 mGal) (2.69 mGal). precision advantage offshore areas. HY-2A-measured have an important role recovery areas complex coastlines many islands. concluded reach international advanced level altimeter-derived model, especially area. freely available at https://doi.org/10.5281/zenodo.6668159 (Zhu et al., 2022).