基于VGOS单基线的UT1测定能力评估  

The Evaluation of UT1 Measurement Based on VGOS Single Baseline Observation

作　　者：姚当 张志斌[1] 李金岭[1] 王广利[1] YAO Dang;ZHANG Zhi-bin;LI Jin-ling;WANG Guang-li(Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030)

机构地区：[1]中国科学院上海天文台,上海200030

出　　处：《天文学报》2023年第1期25-33,共9页Acta Astronomica Sinica

基　　金：地理信息工程国家重点实验室基金项目(SKLGIE2021-M-1-1)资助。

摘　　要：对2021年VLBI (Very Long Baseline Interferometry)全球观测系统(VLBI Global Observing System,VGOS)单基线开展的1 h世界时(Universal Time, UT1)加强观测数据进行分析,结果表明, VGOS单基线测得的UT1与IERS (International Earth Rotation Service) C04序列提供的UT1之差的RMS (Root Mean Square)为25.3μs,优于传统S/X双频段UT1加强观测(Intensive observation, INT1)试验的28.2μs,且UT1的平均形式精度提高1倍.因VGOS单基线1 h观测数目比INT1多1倍,其测得的UT1受极移误差的影响更加稳定,每100μas的极移误差将对UT1引入2.8μs的偏移.此外分析了VGOS 30 min观测数据,除平均形式精度变差外, UT1测量结果与1 h结果相当,表明VGOS单基线30 min观测可用于UT1的超快速服务.同时分析和评估了2021年国内佘山与南山13 m VGOS基线的UT1加强观测能力,统计得到8次观测的RMS为46.2μs,平均形式误差为17.7μs,相比佘山25 m和南山25 m天线的S/X双频观测有显著提升.The one-hour UT1(Universal Time) intensive observations carried out by VGOS(VLBI((Very Long Baseline Interferometry)) Global Observing System) single baseline in 2021 are analyzed. It shows that the RMS(Root Mean Square) of the difference between UT1 measured by VGOS and UT1 provided by IERS(International Earth Rotation Service) C04 is 25.3 μs, which is better than 28.2 μs of traditional S/X UT1 intensive observation(INT1), and the mean formal error of UT1 is improved from 14 μs to 7 μs. Because the scan number of VGOS observations is twice that of INT1 in one hour, the measured UT1 is more stable under the impact of errors in polar motion. 100 μas errors in polar motion will introduce a 2.8 μs offset in UT1. In addition, the data of VGOS half-hour observation is analyzed. The UT1 result is equivalent to the one-hour, indicating that the VGOS half-hour observation can be used for the ultra fast service of UT1. At the same time, this paper analyzes and evaluates one-hour UT1 intensive observation on Sheshan 13 m and Nanshan 13 m baselines. The RMS of eight observations is 46.2 μs and the average formal error is 17.7 μs, which is significantly improved compared with the Sheshan 25 m and Nanshan 25 m baselines.

关 键 词：技术:干涉测量 地球 时间 方法:数据分析 

分 类 号：P128[天文地球—天体测量]