地球自转参数预报误差对天文测量影响的分析  

Analysis of astronomical measurement considering effects of earth roration parameter prediction error

作　　者：魏飞 高玉平[1,3] 尹东山[1,3] WEI Fei;GAO Yuping;YIN Dongshan(National Time Service Center,Chinese Academy of Science,Xi'an 710600,China;University of Chinese Academy of Science,Beijing 100049,China;Key Laboratory of Time and Frequency Primary Standards,Chinese Academy of Science,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,北京100049 [3]中国科学院时间频率基准重点试验室,陕西西安710600

出　　处：《测绘通报》2023年第8期102-107,125,共7页Bulletin of Surveying and Mapping

基　　金：国家自然科学基金(11973046,41804034)。

摘　　要：由于地球自转参数(ERP)的滞后性,目前主要使用国际地球自转和参考服务IERS发布的Bulletin A(简称A公报)预报值进行解算,ERP预报误差对于天文测量的影响目前缺少系统的研究。为此,本文选取IERS 2015—2021近7年A公报的ERP参数对其长期预报及不同时间跨度预报误差分析,并以某站数字天顶望远镜观测结果为例,分析了ERP预报误差对于天文测量的影响。结果表明,随着时间的增加,预报精度越来越差,对于极移参数,1年跨度的预报误差值达到了0.021 as,预报误差对天文经、纬度及方位角的影响分别为0.045 as、0.041 as和0.042 as,完全满足一等天文测量的精度要求;而UT1-UTC预报精度是限制A公报精度的主要因素,60天UT1-UTC的预报误差值已达到了0.007 s,对天文经度的影响达到了0.379 as,已超出一等天文测量的精度要求。为了满足一等天文测量的要求,选取UT1-UTC预报值时,其时间跨度最大为40 d。Due to the hysteresis of earth rotation parameters(ERP),currently only the forecast values of Bulletin A(referred to as Bulletin A)provided by the IERS are used for calculation,however,the effect of ERP forecast errors on astronomical measurement is currently lacking systematic research.To this end,this paper selects the forecast errors of IERS 2015—2021 Bulletin A in the past 7 years to analyze its long-term forecast and forecast errors in different time spans,and takes the observation results of digital zenith telescope at a station as an example to analyze the effect of the Bulletin A forecast error on astronomical measurement.It shows that with the increase of time,the forecast accuracy is getting worse and worse.The forecast error for one-year span of the polar shift reaches 0.0214 as,The effect of polar shift prediction error on astronomical longitude、latitude and astronomical azimuth is 0.045 as、0.041 as and 0.042 as,which fully meets the accuracy requirements of first-class astronomical measurements.The UT1-UTC prediction accuracy is the major factor limiting the accuracy of the Bulletin A.The prediction error of UT1-UTC in a 60-day span reaches 0.007 s,and the effect on astronomical longitude reaches 0.379 as,which has exceeded the accuracy requirements of first-class astronomical measurements.In order to meet the requirements of first-class astronomical measurements,when the UT1-UTC predicted value is selected,the maximum time span is 40 d.

关 键 词：天文测量 地球自转参数 预报误差 极移 UT1-UTC 

分 类 号：P222[天文地球—大地测量学与测量工程]