基于伪距多路径偏差改正的北斗卫星精密单点定位研究

发布时间：2018-04-28 02:09

本文选题：北斗卫星导航定位系统 + 精密单点定位　；参考：《中国测绘科学研究院》2017年硕士论文

【摘要】：精密单点定位(Precise Point Positioning,PPP)高精度的定位结果是基于对影响定位精度的各种误差改正实现的。经研究发现,北斗卫星的伪距观测值存在与高度角相关的系统偏差,该偏差被在本文称为北斗卫星伪距多路径偏差。北斗卫星伪距多路径偏差的存在对精密定位的研究及其应用产生了较大的影响,因此,针对北斗伪距多路径偏差的分析和改正对提高北斗卫星导航定位精度和应用性能有着重要意义。本文主要对北斗伪距多路径偏差及其改正模型进行了研究,并对改正模型效果进行PPP实验检验,研究方法和研究结论如下:(1)基于MP组合提取北斗伪距多路径偏差并对其特征进行分析。(2)根据北斗IGSO和MEO卫星伪距多路径偏差与卫星高度角相关的特性,本文采用加权分段线性拟合的方法对伪距多路径偏差与高度角关系进行建模,并分析了测站数目及分布对建模的影响。根据GEO卫星伪距多路径偏差具有周期性变化的特性,利用小波变换以及小波分解和重构的方法对其进行改正。(3)为了验证伪距多路径偏差的改正算法的有效性,利用GMSD测站数据计算了北斗卫星伪距多路径偏差改正前后的MW组合序列。结果显示:改正算法基本能够消除MW组合的伪距多路径偏差,宽巷模糊度固定过程中的数据利用率有所提高。(4)本文开发了北斗伪距多路径偏差改正模块,并基于RTKLIB开源代码,研制了北斗.PPP软件。(5)利用10个测站的观测数据,采用传统的无电离层模型,以及精密星历和精密钟差产品,实验结果显示:改正伪距多路径偏差后的静态PPP精度在N、E、U 方向平均提高了 6.8%、9.5%、11.3%,RMS 值平均提高了 1.1cm、1.3cm、2.6cm;改正伪距多路径偏差后的动态PPP精度在N、E、U方向平均提高了 9.1%、1.5%、5.2%,RMS值平均提高了 1.7cm、0.6cm、2.3cm。实验结果表明:经过本文提出的伪距多路径偏差改正模型改正后,北斗PPP的定位精度得到提升。
[Abstract]:Precision single point positioning (Precise Point Positioning) high precision positioning results are based on the correction of various errors that affect the positioning accuracy. It is found that the pseudo-range observation of Beidou satellite has a systematic deviation related to altitude angle, which is called the pseudo-range multipath deviation of Beidou satellite in this paper. The existence of pseudo-range multipath deviation of Beidou satellite has a great influence on the research and application of precision positioning. The analysis and correction of Beidou pseudo-range multipath deviation is of great significance to improve the positioning accuracy and application performance of Beidou satellite navigation. In this paper, the multi-path deviation of Beidou pseudo-range and its correction model are studied, and the effect of the correction model is tested by PPP experiment. The research methods and conclusions are as follows: (1) extracting Beidou pseudo-range multipath deviation based on MP combination and analyzing its characteristics. (2) according to the characteristics of Beidou IGSO and MEO satellite pseudo-range multipath deviation and satellite altitude angle, In this paper, a weighted piecewise linear fitting method is used to model the relationship between pseudo-range multipath deviation and height angle, and the influence of the number and distribution of stations on the modeling is analyzed. According to the periodic variation of pseudo-range multipath deviation of GEO satellite, wavelet transform and wavelet decomposition and reconstruction are used to correct the pseudo-range multipath deviation. The MW combination sequence before and after correction of pseudo-range multipath deviation of Beidou satellite is calculated by using GMSD station data. The results show that the correction algorithm can basically eliminate the pseudo-range multi-path deviation of MW combination, and the data utilization rate in the process of fixed ambiguity in wide lane is improved. 4) this paper develops the Beidou pseudo-range multi-path deviation correction module, and based on the RTKLIB open source code, Beidou. PPP software. Y5) using the observation data of 10 stations, using the traditional ionospheric model, precision ephemeris and precision clock difference products, The experimental results show that the static PPP accuracy after correction of pseudo-range multipath deviation is increased by an average of 6.8cm / 9.5cm and 11.3cm / 2.6cm respectively, and the dynamic PPP accuracy after correction of pseudo-range multipath deviation is improved by 9.1cm ~ (1.5) / 5.2cm ~ (-1) cm ~ (-1) and 1.7cm ~ (0.6) cm ~ (0.6) cm ~ (-1) 路cm ~ (-1) 路m ~ (-1), respectively. The experimental results show that the positioning accuracy of Beidou PPP is improved after the correction of pseudo-range multipath error correction model proposed in this paper.
【学位授予单位】：中国测绘科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P228.4

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