北斗卫星伪距多路径系统偏差的修正方法及其对单频PPP的影响分析

发布时间：2018-09-19 13:48

【摘要】：北斗伪距观测值存在特有的多路径系统性偏差,偏差的数量级达到几个分米到米。该系统偏差可分为两类:一类是IGSO/MEO卫星随高度角变化的伪距系统性偏差;另一类是GEO卫星(高度角仅微小变化)明显的伪距系统性偏差。系统性的伪距偏差导致GEO卫星MP序列的标准偏差较大,本文针对GEO卫星伪距偏差问题提出了一种基于卡尔曼滤波的修正方法,修正后的GEO卫星MP序列的标准偏差下降了10%~16%。基于伪距相位组合的单频PPP技术的伪距权重较大,会受到北斗伪距偏差的影响,分析表明该系统性偏差将导致单频PPP定位结果高程方向产生约1m的偏差。对GEO伪距偏差采用提出的卡尔曼滤波修正方法进行修正,并应用Wanninger和Beer的高度角模型消除IGSO/MEO观测值伪距偏差,本文对修正后的单频精密单点定位精度进行了分析。4个multi-GNSS experiment(MGEX)站10d观测数据的分析结果表明:仅改正和卫星多路径误差,高程方向定位结果精度可改善65%左右;采用本文方法对GEO卫星的多路径修正后,该方向定位结果精度改善比例将进一步提高至75%左右。
[Abstract]:The observed values of Beidou pseudo-range have special multipath systematic deviation, the order of deviation is several decimeter to meters. The system deviations can be divided into two categories: one is the pseudo-range systematic deviation of IGSO/MEO satellite with the variation of altitude angle, the other is the obvious pseudo-range systematic deviation of GEO satellite. The systematic pseudo-range deviation leads to the large standard deviation of GEO satellite MP sequence. In this paper, a modified method based on Kalman filter for GEO satellite pseudo-range deviation is proposed. The modified GEO satellite MP sequence standard deviation is reduced by 10% and 16%. The pseudo-range weight of single-frequency PPP technology based on pseudo-range phase combination is large, which will be affected by Beidou pseudo-range deviation. The analysis shows that the systematic deviation will lead to a deviation of about 1m in the elevation direction of single-frequency PPP positioning result. The proposed Kalman filter correction method is used to correct the GEO pseudo-range deviation, and the height angle model of Wanninger and Beer is used to eliminate the pseudo-range deviation of IGSO/MEO observations. In this paper, the accuracy of single frequency precise single point positioning is analyzed. The analysis results of 10 d observation data of four multi-GNSS experiment (MGEX) stations show that the accuracy of elevation direction positioning can be improved by about 65% only by correcting the satellite multipath error. After the multipath correction of GEO satellite is adopted, the accuracy of this direction positioning result will be further improved to about 75%.
【作者单位】：海军工程大学;千寻位置网络有限公司;
【基金】：国家自然科学基金(41631072;41504029)~~
【分类号】：P228

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