中文摘要：

利用全球分布的MGEX站观测数据,使用＂两步法＂以双差方式对北斗卫星进行精密定轨。主要研究北斗卫星轨道确定的处理策略,重点分析轨道确定的流程,并通过实验评价了3种不同类型轨道的精度。结果显示,MEO和IGSO卫星的定轨内符合精度优于0.2m,其中径向优于10cm,外符合精度优于30cm;GEO（以C05号为例）卫星外符合精度优于0.7m,且径向优于10cm。

英文摘要：

The double-difference method is used to determine the Beidou navigation satellite system orbit with multi-GNSS experiment （MGEX） data. This paper mainly studies the precise orbit determi- nation （POD） strategy of Beidou satellite orbit, then discusses the basic process of determining Beidou navigation constellation orbits. Finally, based on observation data, the paper determines the three-day orbit solution of Beidou navigation constellation. The experimental results show that the internal pre- cision of the 1D RMS of MEO and IGSO satellites in orbit determination is better than 0.2 m, the radial direction could be better than 10 cm, and outer precision is better than 30 cm; furthermore, GEO （the C05） satellite outer precision is better than 0.7 m, and the radial direction could be better than 10 cm.