GNSS卫星精密定轨全球地面基准站网随机优化算法

Stochastic Optimization on Global Ground Reference Station Network for GNSS Satellite Precise Orbit Determination

为确保GNSS精密定轨精度和可靠性,需要顾及站点稳定性和观测质量等信息,在全球范围内均匀选取一定数目的地面基准站。在探讨测站数量和分布对导航卫星精密定轨影响的基础上,针对GNSS定轨地面跟踪站在全球分布不均匀的现状,综合考虑站点几何分布、站点稳定性和观测质量信息,提出基于格网控制概率下的全球测站随机优选方法。该方法综合利用格网方法和随机优化方法,通过全球测站分配一定的概率,进而随机抽样和筛选得到全球均匀分布的测站构型。实验结果显示,该方法在全球范围内选取30个测站时,GPS精密定轨的精度能达到2.15 cm,60个测站时,定轨精度优于1.26 cm;90个测站时,定轨精度可提高到1 cm以内。

The influence of the number and distribution of ground tracking stations on the precision orbit determination of navigation satellites is analyzed, and a stochastic optimization method for selecting the ground tracking stations for GNSS satellite precise orbit determination is proposed. The proposed method takes the information such as site location and quality into account, by assigning a certain probability to the global station. An algorithm is designed to optimally select a set of IGS ground tracking stations to achieve GPS satellite precise orbit determination of high precision. The results show that, based on the proposed method, by using 30 stations, the optimally-selected GPS precision orbit accuracy can reach 2.15 cm, while by using 60 stations the accuracy is better than 1.26 cm, the number of stations reaches 90, the precision of orbit determination can be increased to 1 cm.