Assessment About Parameters Selection Strategy of ECOMC Solar Radiation Pressure Model for BDS-3 Satellites During the Earth Eclipsing Period

Solar radiation pressure perturbation is the dominant error of POD of navigation satellites, which is directly bound up with the attitude control strategy of satellites and the properties of surface materials. Because of the difference of satellite characteristics, the 5-parameter ECOM model is not completely suitable for BDS-3 satellites during the earth eclipsing period. The higher-order periodic terms of ECOMC model can effectively absorb errors such as thermal radiation that are not modeled during the earth shadow period. This paper studies the variation of D₀, Y₀ and B₀ of ECOMC model with the sun elevation angle, proves that compared with the 5-parameter ECOM model, the ECOMC model is more accurate for navigation satellites POD. In order to solve the problem of excessive parameterization of ECOMC model, this paper analyzes the correlation between 13 solar radiation pressure parameters of ECOMC model. Based on the strong correlations, the 11-parameter ECOMC model for CAST satellites without estimating B_c and D_4c parameters and the 12-parameter ECOMC model for SECM satellites without estimating Bc12 parameters are proposed respectively. The experimental results show that compared with the 5-parameter ECOM model, the 11-parameter ECOMC model of CAST satellites can improve the radial, along-track and cross-track accuracy by 74.0%, 65.5% and 61.3%, respectively, and the 1DRMS by 66.7% during the Earth Eclipsing period. The 12-parameter ECOMC model for SECM satellites can prove the radial, along-track and cross-track accuracy by 58.5%, 56.2% and 70.7%, respectively, and the 1DRMS accuracy by 60.0% during the Earth Eclipsing period.