What Can We Expect from the Inclined Satellite Formation for Temporal Gravity Field Determination?

Abstract

The assumption of implementing a Bender-type mission with two pairs of inline satellites by two institutions, one in the inclined satellite formation (ISF) and the other in the polar satellite formation (PSF), has been proven as an optimal selection for the next-generation gravimetric mission (NGGM). The prerequisite of this assumption is to ensure the combination as well as the independency of the missions in the PSF scenario as well as in the ISF scenario. To promote NGGM, we implement a close-loop simulation study to evaluate the performance of the stand-alone ISF mission. In the spectral domain, the ISF estimations show extremely poor quality for zonal and near-zonal coefficients due to the absence of observations over the polar regions, while the sectorial and near-sectorial coefficient estimations show approximately 71 ~ 77% noise reductions when compared with the PSF estimations. In the spectral domain, the ISF mission presents its superior capability in detecting the Earth’s mass variations within its observational areas than the PSF mission. The improvements of ISF are also obtained over the transition zones (50°N ~ 70°N and 50°S ~ 70°S) with 41% noise reductions. In addition, the general better performance of gravity estimations via ISF may promote the potential geoscience applications over the small river basins, the coastal ice sheet and the earthquake areas with better accuracy and finer resolution. The simulation results demonstrate the feasibility of implementing a stand-alone mission in the inclined orbits, and the further possibility of promoting a Bender-type mission via a profound cooperation by two institutions.