区域GNSS网的整数卫星钟差解算

Integer Satellite Clock Estimation with Regional GNSS Network

基于双差模糊度的整数性质,从理论上证明,通过固定基准模糊度可以使整网的星间单差模糊度都恢复整数性质,实现星间单差模糊度固定,从而得到整数卫星钟差。提出模糊度连续弧段的概念,改进基准模糊度选取方法。实验表明,对于1 d弧长的区域观测网数据,与旧方法相比,新方法获得的基准模糊度的数量增加近1倍;基准模糊度固定之后,窄巷模糊度成功固定的比例从60%左右提高到90%左右。将得到的整数卫星钟差用于30 min弧长的快速静态PPP,实现固定解的比例为96.00%。模糊度固定之后,PPP定位N、E、U方向的RMS分别达到7.3 mm、9.8 mm、23.3 mm。

Based on the integer property of double-difference ambiguity,we prove that the integer property of between-satellite single-difference(BSSD)ambiguities would be invoked once the basis ambiguities are successfully fixed.In order to select a group of independent BSSD ambiguities as a“complete”datum,the concept of ambiguity-continuity-arc is proposed,along with a strategy for selecting basis ambiguities.An experiment is carried out to validate the novel approach.The total number of basis ambiguities is about 2 times that achieved by the old method,resulting in the percentage of fixed BSSD ambiguities improved from about 60%to about 90%,after the basis ambiguities are fixed.The clock products obtained with the proposed approach are validated with rapid static precise point positioning.We show that the percentage of ambiguity-fixed solution is 96.00%,and the RMS in north,east and up directions are 7.3 mm,9.8 mm and 23.3 mm,respectively.