利用恒星日滤波改进精密单点电离层延迟提取  

Improving Real-Time Ionospheric Delay Extraction in Precise Point Positioning with Sidereal Filtering

作　　者：郑彬[1,2] 王宇[2] 欧钢[1] 

机构地区：[1]国防科技大学电子科学与工程学院,湖南长沙410073 [2]江南计算技术研究所,江苏无锡214083

出　　处：《武汉大学学报（信息科学版）》2016年第7期983-988,共6页Geomatics and Information Science of Wuhan University

基　　金：新世纪优秀人才支持计划(NCET-04-0995)~~

摘　　要：利用非组合精密单点定位(PPP)可以提取高精度的电离层延迟。测站多径误差会影响伪距和相位测量精度,影响实时PPP电离层延迟提取的精度以及收敛速度。对于静态观测站,利用对GPS卫星地面跟踪的时间重复性进行恒星日滤波可以消除多径误差的影响。通过事后处理提取前几日的码和载波相位残差序列,利用恒星日滤波建立多径误差改正模型,修正实时观测数据,可以改善实时电离层延迟估计性能。对IGS观测站的实测数据分析表明,应用恒星日滤波多径误差修正后,实时电离层延迟提取的精度由0.185m提高到0.028m,新进卫星的电离层参数估计收敛时间由80min减少为35min。Uncombined precise point positioning（PPP）could be used to extract ionospheric delay with high accuracy.However,parameters estimation in PPP requires long converge time due to the high correlation between ionosphere and ambiguity parameters.Further more,the multipath effects at tracking station degrade the precision of code and phase measurements,thus impact the performance of PPP ionospheric delay estimation.For static observation stations,sidereal filtering could be used to eliminate multipath errors by taking advantage of the ground track repeat period of GPS satellites.After extracting the code and carrier phase residuals of the past few days in post-processing,multipath error correction model could be established with historical residual series by sidereal filtering,so as to improve the performance of real-time ionospheric delay estimation.Experiments with IGS observation data showed that with the application of sidereal filtering,real-time ionospheric delay extraction error decreased from 0.185 mto 0.028 mand convergence time of ionospheric parameters for newly rising satellites reduced from 80 minutes to 35 minutes.Improvements in single station ionosphere delay estimation could refine ionosphere model of local network.On the other hand,precise satellite slant ionosphere delay can be obtained at a lower elevation,which can reduce the layout density need of reference station network.

关 键 词：精密单点定位 电离层延迟 多径误差消除 恒星日滤波 

分 类 号：P228.41[天文地球—大地测量学与测量工程]