Compared to the BeiDou regional navigation satellite system (BDS-2), the BeiDou global navigation satellite system (BDS-3) includes the newly designed B1C and B2a signals, which are compatible with the L1 and L5 frequencies of the global positioning system (GPS). Considering that the precise orbit determination (POD) of the BDS-3 constellation is currently restricted to the legacy B1I and B3I signals, we reported the POD performance of BDS-3 satellites using B1C and B2a dual-frequency measurements. Nine globally distributed Multi-GNSS Experiment (MGEX) stations were selected to determine the orbits of BDS-3 satellites during the period of July 2019. The results show that B1C/B2a-based POD enables an average three-dimensional root-mean-square error (3D RMS) of 24.2 cm, and the precision is better than 6 cm in the radial component in a comparison of two-day overlapping arcs. Satellite laser ranging (SLR) validation achieves an overall precision of 6.8 cm in RMS differences. Compared to the B1I/B3I-based POD results, the quality of B1C/B2a-based orbits is improved by approximately 9% across the whole BDS-3 constellation, indicating that the new B1C/B2a signals can be employed for the superior POD performance of BDS-3 satellites. Moreover, we investigated the behavior of the solar radiation pressure (SRP), which is generally considered one of the primary error sources in BDS-3 medium earth orbit (MEO) dynamic orbit determination. The ECOM7 SRP model has a better POD performance in continuous yaw steering (CYS) mode than the ECOM5 and ECOM9 SRP models. The results also show that there is no degradation in the orbit precision of BDS-3 MEO satellites when the elevation angle of the sun above the orbital plane (β angle) varies within the range of − 4° to + 4°.

与北斗区域导航卫星系统（BDS-2）相比，北斗全球导航卫星系统（BDS-3）包括新设计的B1C和B2a信号，它们与全球定位系统（GPS）的L1和L5频率兼容）。考虑到BDS-3星座的精确轨道确定（POD）当前仅限于传统的B1I和B3I信号，我们使用B1C和B2a双频测量报告了BDS-3卫星的POD性能。选择了9个全球分布式Multi-GNSS实验（MGEX）站来确定BDS-3卫星在2019年7月期间的轨道。结果表明，基于B1C / B2a的POD可以实现平均三维均方根24.2厘米的误差（3D RMS）与两天重叠弧的比较，径向分量的精度优于6 cm。卫星激光测距（SLR）验证在RMS差异方面实现了6.8 cm的整体精度。与基于B1I / B3I的POD结果相比，基于B1C / B2a的轨道质量在整个BDS-3星座中提高了大约9％，这表明可以将新的B1C / B2a信号用于卓越的POD性能BDS-3卫星。此外，我们研究了太阳辐射压力（SRP）的行为，通常将其视为BDS-3中地球轨道（MEO）动态轨道确定中的主要误差源之一。与ECOM5和ECOM9 SRP模型相比，ECOM7 SRP模型在连续偏航操纵（CYS）模式下具有更好的POD性能。