基于条件数的CORS系统流动站参考卫星选择方法

Reference satellite selection method for CORS rover station based on condition number

针对CORS系统流动站常遇到的可解算卫星数量少、卫星分布不均匀问题,提出了一种基于条件数的参考卫星选择方法.首先,从载波双差定位模型出发,分析了参考卫星与非参考卫星组成的卫星对几何分布对载波双差方程间相关性的影响,阐明了载波双差方程间相关性与病态性的本质关系.然后,提出了一种基于法方程矩阵最小条件数的参考卫星选择方法,以优化双差观测结构,并将定位解算结果与采用常规的基于高度角最高原则的参考卫星选择方法所得结果进行了对比.实验结果表明,在CORS系统流动站卫星分布较差的情况下,所提方法的定位结果明显优于常规方法,特别是在高程方向上精度平均提高了约41.7%.

Aiming at the problem of few and uneven-distributed satellites at a CORS （continuous operational reference system）rover station,a new reference satellite selection method based on condition number was proposed.First,according to the double differential （DD）carrier model,the influence of the geometry of the satellite pair composed by reference and non-reference satellites on the correlation of the DD carrier phase equations was analyzed.The critical relationship between the correlation of the DD carrier phase equations and the ill-condition level was described.Then,a reference satellite selection method based on the minimum condition number was proposed to optimize the DD observation structure.The positioning results by the proposed method and those by the conventional method with the principle of maximum elevation were compared.The experimental results show that when the satellite distribution at the CORS rover station is poor,the positioning results by the proposed method are obviously better than those by the conventional method.In particular,the average increase of the height accuracy is about 41.7%.