IVS分析中心EOP产品及精度评估

介绍了国际测地/天体测量学甚长基线干涉测量服务(International Very Long Baseline Interferometry (VLBI) Service for Geodesy and Astrometry, IVS)组织机构及下属分析中心概况.系统归纳了目前IVS发布的地球定向参数(Earth Orientation Parameters, EOP)产品类型及不同观测类型的用途.利用2010—2019年公开发布的观测资料,对IVS不同分析中心的EOP日常监测和服务能力进行了评估.通过构造观测台站所构成的几何体积,分析了EOP精度与测站数量、测站网分布的关系,统计了IVS不同观测类型的EOP解算精度.此外,综合公开发布的美国、欧洲等区域网观测数据,分析了不同地区区域网的常规及加强观测结果与IVS结果的差异.结果表明:EOP的解算精度与观测台站的分布密切相关, IVS常规观测确定的极移分量的外符合精度优于0.2 mas,世界时(Universal Time, UT1)与协调世界时(Coordinated Universal Time,UTC)之差(UT1-UTC)的精度在0.015 ms左右,加强观测的UT1-UTC值与国际自转服务组织(International Earth Rotation Service, IERS)的C04之间存在0.02–0.03 ms的差异.区域观测网的精度受观测网形和基线长度制约,总体劣于IVS观测精度,其中,美国甚长基线干涉阵列(Very Long Baseline Array, VLBA)的常规及加强观测结果与IVS全球观测结果最接近.

EOP Products of IVS Analysis Center and Its Precision Evaluation

The organization and subordinate analysis center of International Very Long Baseline Interferometry (VLBI) Service for Geodesy and Astrometry (IVS) are introduced. The types of earth orientation parameters (EOP) products currently released by IVS and the uses of different observation types are summarized systematically. Based on the observation data published from 2010 to 2019, this paper evaluates the overall service capacity of IVS regular observation and intensive observation products of different analysis centers. By constructing the geometric volume formed by observation stations, the relationship between EOP accuracy and the number of observation stations,the distribution of the station network is analyzed, and the calculation accuracy of EOP for different observation types of IVS is counted. Besides, compared with observation data of regional networks in the United States and Europe publically on the website, the differences between the regular observation and intensive observation results of regional networks in different regions and IVS results are analysed. The results showed that the accuracy of EOP is closely related to the distribution of observation stations. The external coincidence precision of the polar motion component determined by IVS conventional observation is better than 0.2mas, the precision of UT1-UTC (the difference between Universal Time (UT1) and Coordinated Universal Time (UTC)) is about 0.015 ms, and the UT1-UTC value of intensive observation has a difference of 0.02--0.03ms from International Earth Rotation Service (IERS) C04 products.\lk The precision of the regional observation network is restricted by the shape of the observation network and the length of the baseline, which is generally inferior to the observation precision of IVS. Among them, the regular and intensive observation results of the Very Long Baseline Array (VLBA) network in the United States are the closest to the global observation results of IVS.