Research Status and Progress in International Next-Generation Satellite Gravity Measurement Missions

We review the development of the satellite gravity measuring techniques. The research status of present satellite gravity missions, including CHAMP, GRACE, and GOCE, are discussed and the main shortcomings of GRACE are analyzed. Some suggestions for determining gravity field at higher precision and higher resolution in space and time are proposed, which include reduction of the current level of aliasing, the elimination of systematic distortions (non-isotropic sensitivity of a single pair low-low SST), and the improvement in the separability of the observed geophysical signals are discussed. The progress of the next four international satellite gravity missions: E.motion, GRACE-FO, NGGM, GETRIS, are presented and the role and status of the SWARM satellite constellation mission on the earth's gravity field research are summarized. Finally, several suggestions about the implementation of the future satellite gravity missions in China are put forward. The next generation satellite gravity systems should be capable of global determination of changes in the Earth's gravity field from global down to regional spatial scales and at time scales of two weeks or shorter.