Solar radiation pressure modeling for BDS-3 MEO satellites precise orbit determination

The empirical 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 MEO satellites determined with the ECOM model display a systematic dependency with respect to β-angles or ε-angles. BDS-3 MEO satellites, characterized by a stretched satellite body and an extra SAR antenna carrying, contribute to the observed systematic variations. In this study, we established an a priori SRP model for BDS-3 MEO satellites using various approaches to enhance the ECOM. With these model, precise BDS-3 MEO orbits in 2023 were determined. SLR validation indicated that the systematic ε-angles or β-angles-dependent error was reduced. In general, a standard deviation (STD) of SLR residuals better than 4 cm was achieved, and also an improvement of 1–2 times over the five-parameter ECOM model was obtained.