Time-Variable Gravity Field from the Combination of HLSST and SLR

The Earth’s time-variable gravity field is of great significance to study mass change within the system. Since 2002, NASA-DLR Gravity Recovery and Climate Experiment (GRACE) its successor GRACE follow-on mission provide observations monthly changes in Earth with unprecedented accuracy resolution by employing low-low satellite-to-satellite tracking (LLSST) measurements. In addition LLSST, models can be acquired from satellite laser ranging (SLR) high-low (HLSST). solutions HLSST+SLR were derived combining HLSST low earth orbiting (LEO) satellites SLR geodetic satellites. Bandpass filtering was applied harmonic coefficients reduce noise. this study, we analyzed performance spectral spatial domains. results show that: (1) accuracies are comparable those for below degree 10, significantly improved compared SLR-only HLSST-only solutions; (2) effective could reach 1000 km, corresponding spherical coefficient 20, which higher than that solutions. Compared solutions, global redistribution features magnitudes well identified at although much applications regional recovery, seasonal variations over Amazon Basin long-term trend Greenland truncated 20 agree without truncation, RMS 282 Gt 192 Greenland. We conclude an alternative option estimate temporal field, far less lower offered GRACE. This approach monitor large-scale transport during data gaps between missions.