基于GNSS加密网的VLBI电离层时延修正方法  

Ionospheric TEC Correction for VLBI Based on GNSS Density Network

作　　者：周伟莉[1,2,3] 宋淑丽 李培佳[1] 张志斌[1,3] 黄超[1,3] 黄勇 王广利[1] ZHOU Weili;SONG Shuli;LI Peijia;ZHANG Zhibin;HUANG Chao;HUANG Yong;WANG Guangli(Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China;National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海天文台,上海200030 [2]中国科学院国家空间科学中心,北京100190 [3]中国科学院大学,北京100049

出　　处：《深空探测学报（中英文）》2020年第4期362-370,共9页Journal Of Deep Space Exploration

基　　金：国家重点研发计划资助项目(2016YFB0501503);国家自然科学基金资助项目(41730109)。

摘　　要：基于全球导航卫星系统(Global Navigation Satellite System,GNSS)反演的电离层模型是甚长基线干涉(Very Long Baseline Interferometry,VLBI)网(Chinese VLBI Network,CVN)电离层时延修正的有效方法。由于国际GNSS服务组织(International GNSS Services,IGS)跟踪网在中国区域较稀疏,针对探月工程高精度需求,提出了加密GNSS跟踪网的处理策略,构建了全球电离层精修正模型(ShangHai Astronomical Observatory,SHAO),并与欧洲定轨中心发布的全球电离层修正模型(Center for Orbit Determination in Europe,CODE)作对比。结果表明:在电离层平静期,采用两种模型计算的CVN站电离层时延相对均方根误差(Root Mean Square Error,RMSE)最大1.23 ns;在电离层活跃期,CVN站的电离层时延RMSE最大达16.80 ns。在电离层处于活跃期时,基于SHAO模型的VLBI定轨残差相比CODE模型在S1波段由6.07 ns提高到3.33 ns,S2波段由9.10 ns提高到7.07 ns,X0波段由0.70 ns提高到0.60 ns。Very long baseline interferometry(VLBI)is one of the key technologies for orbit determination of Chang’-E satellites in China’s lunar exploration project.Ionospheric delay is one of the main errors of VLBI orbit determination.The ionospheric delay correction method based on GNSS inversion is given,which is used in the Chinese VLBI Network.Because there are few stations of international GNSS service(IGS)in China,in order to meet the demand of lunar exploration,more stations are will be builtin China and a new global ionospheric correction model(SHAO)is constructed.Compared with the CODE model,the maximum difference of ionospheric delay Root Mean Square Error(RMSE)on CVN stations is 1.23 ns during the ionospheric quiescence.During the active period of the ionosphere,the maximum difference of the ionospheric delay RMSE on CVN station is 16.80 ns.When the ionosphere is active,the VLBI orbit determination residual based on the SHAO model increases from 6.07 ns to 3.33 ns in S1 band,9.10 ns to 7.07 ns in S2 band,0.70 ns to 0.60 ns in X0 band compared with CODE model.

关 键 词：探月工程 VLBI 电离层时延 GNSS 

分 类 号：P135[天文地球—天体力学] P164[天文地球—天文学]