基于小波分析提取单频GNSS伪距多路径误差及其对定位的影响

伪距多路径误差是影响GNSS导航定位精度的主要误差源之一。多路径误差与接收机周围环境有关,在实际应用中难以建立有效的多路径误差模型进行改正。对于多频GNSS接收机可以通过多频观测值组合估计伪距多路径,但该方法不适用于价格低廉的单频接收机,而导航中使用的大多数为单频接收机。因此,开展单频GNSS伪距多路径误差提取研究具有重要的工程应用价值。本文基于小波分析对单频GNSS接收机伪距多路径误差估计开展研究,首先验证了小波分析用于单频GNSS伪距多路径误差估计的可行性;其次,研究了采用不同的小波基和分解层次对多路径误差估计的影响;最后,研究了改正多路径误差对GNSS定位的影响。实验结果表明不同的小波基和分解层次对多路径误差提取效果没有明显的差别,但小波分解层次较低时定位误差分布相对更加集中,同时,经过多路径误差改正后在NEU3个方向RMS平均改善率达到20.4%、25.1%、16.4%。

Extraction of Multipath Error Information of Single Frequency GNSS Signals Based on Wavelet Analysis and Evaluate Effect on Positioning

Pseudorange multipath is one of the main error sources affecting GNSS navigation positioning accuracy.It is related to the environment around the receiver.It is difficult to establish an effective multipath error model to correct it in practical application.For multi-frequency GNSS receivers,pseudorange multipath can be estimated by combining multi-frequency observations,but this method is not suitable for low-cost single-frequency receivers,and most of the single-frequency receivers used in navigation are single-frequency receivers.Therefore,the research on pseudorange multipath error extraction of single frequency GNSS has important engineering value.this paper studies pseudorange multipath error estimation of single frequency GNSS receiver based on wavelet analysis.Firstly,to verify the feasibility of applying wavelet analysis to pseudorange multipath error estimation of single frequency GNSS.Then,to study the influence of different wavelet bases and decomposition levels on multipath error estimation.Finally,to study the influence of correcting multipath error on GNSS location.The results of RMS statistics show that the effect of different wavelet bases and decomposition levels on multipath error correction is not much different,but the location distribution is more concentrated when the decomposition level is lower.At the same time,after multipath error correction,the RMS in North,East,Up direction are improved by 20.4%,25.1%and 16.4%,respectively.