Multi-satellite combined orbit determination integrative fusion models with applications

Abstract

For multi-LEO combined orbit determination (COD) satellite-network based on space-based tracking telemetry and command (STTC) satellites, kinematic orbit information can be obtained only using the method of precise point positioning (PPP) based on observation models, but the orbits results are not very precise because of the precision of observation data and the Geometry Dilution of Precision (GDOP) of STTC constellation. If kinematic orbit information of low earth orbit (LEO) satellite-network can be taken full advantage of participating in dynamic precise orbit determination (POD) and making them achieve best matching, namely integrative COD models based on kinematic and dynamic information are brought forward in this paper to realize dynamic smoothness of kinematic orbit information, which hopefully can be gained more perfect COD precision of LEO satellite-network. Firstly, single LEO kinematic method based on difference positioning model and the corresponding algorithm was designed, and integrative COD models of COD satellite-network were constituted based on kinematic orbit information of PPP method and dynamic trajectory information. Then integrative COD fusion models based on prior trajectory information were established, and the optimal weighting algorithm of multi-structural nonlinear COD models based on extended prior information was designed. Theoretical analysis and simulation computation results show that COD weighting method based on prior trajectory information can realize LEOs dynamic information optimal matching with kinematic prior information, and can restrain nonlinear influence factor including measure models errors and ephemeris errors to the effects of POD precision by considering models errors modeling and dynamic models sparse parameters denotation, which further ameliorate COD precision of STTC satellite constellation and LEOs.