The analytical methods for gravity field measurement performance of satellite formation

Abstract

Compared with gravity field measurement missions of low-low satellite-to-satellite tracking, for example GRACE, and GRACE follow-on, satellite formation can greatly improve the resolution and accuracy of gravity field measurement because of adding inter-satellite range-rate measurements in radial and normal direction. So it is important to pay more attentions on gravity field measurement of satellite formation. The physical mechanism of obtaining gravity signals via satellite payloads is a fundamental question in satellite formation gravity measurement. Because of multiple gravity satellite payloads and strong coupling between these payloads, mission design strongly depends on computer simulations, with suboptimal designs only achieved. The effective way of optimisation design of satellite formation mission has not been found. To solve this problem, firstly the analytical model of gravity field measurement of satellite formation is established by combining gravity field measurement performance of low-low satellite-to-satellite tracking in three orthogonal directions, i.e., the radial, tracking and normal direction. Secondly, based on this analytical model, the influences of orbital altitude, satellite formation configuration parameters, and payload capacities are analysed. Then the optimisation design method of formation configuration and payload capacities are proposed, which provides theoretical basis for mission analysis and design of gravity field measurement.