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由于GPS非差相位观测值的相位偏差(initial phase biases,IPB)与整周模糊度难以分离,精密单点定位(PPP)估值均为模糊度浮点解。首先对GPS原始观测方程的秩亏问题进行分析,从参数整合的角度,推导IPB估计的满秩函数模型,形成一种新的PPP-AR算法。以此为基础,对已有两种算法的特点进行对比分析。研究表明,分解法是一种观测信息的最优利用,且与传统的星钟估计方法具有一致性,但未发掘IPB较为稳定的有利约束;非整法对所采用的组合观测值之间的相关性未加考虑,是一种次优估计,实时性较差,且较依赖于高精度的码观测。推导的新算法可有效克服已有算法的不足,便于施加部分参数的合理时变性约束,提高IPB估计的可靠性。 更多还原

【Abstract】 Due to the inseparability between the initial phase biases(IPB) and the integer ambiguities in un-differenced(UD) GPS carrier phase observable,the solutions from precise point positioning(PPP) are always ambiguity-float.The rank-defect UD GPS observation equation is firstly investigated,and the full-rank mathematical model for satellite IPB estimation is derived by means of re-parameterization,thus forming a new strategy for PPP-AR.Comparative analysis of the characteristics of both existing met... 更多还原