非均一方差的GNSS定位误差模型检验

A Test of GNSS Positioning Error Model of Non-uniform Pseudorange Error

在全球导航卫星系统中,定位精度是一个重要的性能指标。准确的定位误差模型有利于理解系统的工作模式,同时也为进一步提高系统性能提供指导。当卫星的测距误差满足相互独立和方差均一的条件时,定位误差等于测距误差标准差与几何精度因子的乘积。然而在实际应用中,由于不同卫星信号的传播路径不同,测距误差的统计特征难以相同,尤其当卫星信号受到多径干扰与电离层闪烁影响时,不同卫星间的测距误差有显著的差异。介绍了一种利用奇异值分解方法建立的非均一测距误差的定位误差理论模型,利用北京站与香港站的实测数据,对受到多径效应与电离层闪烁影响的定位误差进行分析。结果表明,其统计特性与非均一方差的定位误差模型给出的结果一致,验证了模型的正确性和有效性。

In the global navigation satellite system(GNSS),an accurate positioning error model is important for understanding how the system works.When the pseudorange error of each satellite has an uncorrelated normal distribution with zero-mean and common variance,the positioning error is equal to the standard deviation of pseudorange error multiplied by the geometric precision.However,in practical applications,the pseudorange errors may differ in variance due to the different signal propagation paths.Especially when the signals are affected by multipath effects or ionospheric scintillation,the pseudorange errors will be significantly different from one another.This paper introduces a theoretical positioning error model of non-uniform pseudorange error based on singular value decomposition(SVD).Using GNSS data at Beijing station and Hong Kong station to analyze the positioning errors affected by multipath effects and ionospheric scintillation,the statistical characteristics of positioning error are consistent with the results given by the positioning error model of non-uniform pseudorange error,proving the correctness and validity of the model.