基于国内宽带VLBI2010系统及iGMAS的UT1/ΔLOD数据融合方法  

UT1/ΔLOD data combination method with domestic broadband VLBI2010 system and iGMAS

作　　者：李西顺 吴元伟 姚当 刘佳 马浪明[1,3] 杨旭海[1,3] 张首刚 LI Xishun;WU Yuanwei;YAO Dang;LIU Jia;MA Langming;YANG Xuhai;ZHANG Shougang(National Time Service Center, Chinese Academy of Sciences, Xi’an 710600, China;School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences. Beijing 100049, China;Key Laboratory Positioning and Timing Technology, Chinese Academy of Sciences, Xi’an 710600, China;Key Laboratory of Time and Frequency Primary Standards, Chinese Academy of Sciences, Xi’an 710600, China)

机构地区：[1]中国科学院国家授时中心,陕西西安710600 [2]中国科学院大学电子电气与通信工程学院,北京100049 [3]中国科学院精密导航定位与定时技术重点实验室,陕西西安710600 [4]中国科学院时间频率基准重点实验室,陕西西安710600

出　　处：《系统工程与电子技术》2022年第5期1644-1651,共8页Systems Engineering and Electronics

基　　金：国家自然科学基金面上项目(12073034);中国科学院一带一路团队项目(XAB2018YDYL01)资助课题。

摘　　要：针对国内甚长基线干涉测量(very long baseline interferometry,VLBI)观测频率不足,导致世界时(universal time,UT1)缺乏连续性的现状,提出将国内宽带VLBI系统(VLBI2010)解算的UT1序列及国际全球卫星导航定位系统(global navigation satellite system,GNSS)监测评估系统(international GNSS monitoring and assessment system,iGMAS)解算的日长变化ΔLOD序列进行融合,进而得到更为连续且稳定的UT1序列。该方法的核心是将VLBI2010的UT1序列和iGMAS的ΔLOD序列通过Vondrak算法进行融合,并结合马尔可夫链蒙特卡罗(Markov chain Monte Carlo,MCMC)模拟方法研究了不同测量精度和时间间隔的UT1序列对融合后的UT1精度依赖关系,以及融合过程中UT1和ΔLOD最优权比的选择,最后将融合后的数据与IERS 14 C04 UT1序列进行比对。实验结果表明,2018年和2020年的VLBI2010系统的实测UT1序列与iGMAS的ΔLOD序列融合后,UT1的精度分别达到32μs和51μs,融合后的UT1精度提升超过30%。Due to the lack of observation frequency of very long baseline interferometry(VLBI)in China,universal time(UT1)lacks continuity,a combination approach is proposed by combining the UT1 sequence produced by the domestic broadband VLBI system(VLBI2010)and the variation of length of dayΔLOD sequence produced by the international global navigation satellite system(GNSS)monitoring and assessment system(iGMAS).The Vondrak algorithm is used to combine the UT1 sequence of VLBI2010 and theΔLOD sequence of iGMAS.The Markov chain Monte Carlo(MCMC)simulation is used to investigate the relationship between the combined accuracy of UT1 sequences and the input measurement accuracy and time interval,and the optimization of the weight ratio between UT1 andΔLOD.Finally,the combined UT1 sequence is compared with the IERS 14 C04 UT1 sequence.It is shown that the combination algorithm can effectively improve the accuracy of the output UT1 series:the accuracies of 2018 and 2020 UT1 series are 32μs and 51μs respectively.Compared with the original series,the accuracy of the combined result is improved by more than 30%.

关 键 词：世界时 日长变化 参考系 数值方法 

分 类 号：P228[天文地球—大地测量学与测量工程]