HUST-CRA: A New Atmospheric De-aliasing Model for Satellite Gravimetry

Atmospheric de-aliasing is one of the most important background models for recovering Earth’s temporal gravity field from gravity satellite missions. To meet the needs of China’s gravimetric satellite platform, an independent atmospheric de-aliasing model that relies on Chinese meteorological data needs to be developed. The release of CRA-40, as the first-generation Chinese atmospheric reanalysis, provides the opportunity. This study proposes a revised modeling method to calibrate CRA-40 and develops a new atmospheric de-aliasing model (HUST-CRA, 2002–20). Intensive assessments are made between HUST-CRA and the latest official de-aliasing product of the international gravity satellite mission. The tidal components of the two products demonstrate high consistency, e.g., the spatial correlation for the major tide S1 is 0.96. The non-tidal components of the two products are also equivalent: (1) the temporal correlation of low-degree terms is higher than 0.97, except for the term of S22 (0.93); (2) the spectral correlation of degree geoid height up to degree/order 100 is as high as 0.99; (3) the confidence interval of the spatial correlation (2002–20) is [0.971, 0.995] at a confidence level of 95%; and (4) the difference in KBRR (K-band range rate) residuals is less than 0.08 µm s−1, the difference in the derived temporal gravity field is less than 0.32 mm in terms of geoid height, and both are apparently beyond the ability of the current gravity satellite mission. This confirms that CRA-40 is of high quality and that the derived de-aliasing product, HUST-CRA, is accurate enough to be used in both Chinese and international gravity satellite missions.