Computation of the marine full tensor gravity gradient from satellite altimetry in a local planar coordinate system

Abstract

Marine gravity gradient data, which provide high-precision, multi-component observations, are crucial for detecting subtle variations in oceanic geological structures. This information has profound implications for geological exploration, seabed resource assessment, and seismological research. Typically, satellite altimetry is mainly employed to obtain marine gravity field information. In our study, we proposed a strategy that integrates the deflection of the vertical (DOV), derived from satellite altimetry data, with Fast Fourier Transform (FFT) technology to compute the full tensor of the ocean’s gravity gradient. Initially, the DOV components were estimated using the least squares method from the geoid gradient. Subsequently, the vertical gravity gradient anomaly on the ocean surface was determined utilizing the DOV components. Finally, the remaining five gravity gradient tensor components were derived from the vertical gravity gradient anomaly using FFT techniques. In our experiments, we applied the proposed strategy to SWOT and CryoSat-2 observations. The Scripps Institution of Oceanography model was employed to validate the vertical gravity gradient component, while the results for the full tensor of gravity gradient were verified using the CUGB2023GRAD model. The experimental results validate the processing strategy proposed in this study, demonstrating its effective applicability within the local planar coordinate system.