Modeling and comparison of solar radiation pressure for two BDS-3 MEO satellites (C45 and C46) with SAR payload

The empirical Extended CODE orbit model, including the 5-parameter reduced ECOM (ECOM1) and the 7-parameter extended ECOM model (ECOM2), is extensively utilized for solar radiation pressure (SRP) modeling of BDS-3 MEO satellites. This study shows that Satellite Laser Ranging (SLR) residuals of BDS-3 C45 and C46 satellite orbit determined with the ECOM model display a systematic dependency with respect to -angles or -angles. These two satellites are characterized by a stretched satellite body and an extra Search and Rescue (SAR) antenna, contributing to the observed systematic variations. In this study, the a priori SRP models for C45 and C46 satellites were established based on the adjustable box-wing as well as Fourier transformation to enhance the ECOMa (ECOM + along-track acceleration), and the comparison with ECOM2 was also presented. With these models, precise C45 and C46 orbits in 2023 were determined. SLR validation indicated a reduction in the systematic error dependent on -angles or -angles. In general, a standard deviation (STD) of SLR residuals better than 3 cm was achieved, reflecting an improvement of 2–3 times compared to the ECOM2 model.