随机优化算法的BDS卫星精密轨道确定

Precise orbit determination of BDS satellite based on stochastic optimization algorithm

针对全球北斗地面基准站分布不均匀而影响北斗定轨精度的问题,该文采用格网控制的随机优化选站方法,兼顾测站的质量、分布和站点稳定性等因素,对全球分布的MGEX站均匀选取。运用加权GDOP指标评价选站的有效性,并全面分析了测站数量、分布和质量对定轨精度的影响。结果表明,该方法选取30个测站时,北斗卫星的GEO、IGSO和MEO卫星的精密轨道精度分别为221.56、12.59和6.81cm,比格网法选站有了较大提高。在一定范围内,测站数越多定轨精度越高,全部测站参与解算反而会使定轨精度降低。

In view of the uneven distribution of the BeiDou ground reference station,which affects the accuracy of BeiDou orbit determination,the grid based stochastic optimization method was adopted in this paper,taking account of the quality,distribution and station stability of the stations,the global distribution of MGEX stations was evenly selected.The weighted GDOP index was used to evaluate the effectiveness of the selected stations,and the influence of the number,distribution and quality of the stations on the orbit determination accuracy was comprehensively analyzed.The results showed that the precision orbit accuracy of GEO,IGSO and MEO satellites of BeiDou satellite was 221.56,12.59 and 6.81 cm respectively when 30 stations are selected by this method,there was a greater improvement than the grid method.Within a certain range,the more the number of stations was,the higher the accuracy of orbit determination was.