基于国内VLBI站组网的EOP观测仿真研究  

Simulation of EOP determination using Chinese domestic VLBI network

作　　者：李镕希 吴元伟 冯来平[3] 姚当 杨旭海[1,2] 张首刚 LI Rong-xi;WU Yuan-wei;FENG Lai-ping;YAO Dang;YANG Xu-hai;ZHANG Shou-gang(National Time Service Center,Chinese Academy of Sciences,Xi’an 710600,China;University of Chinese Academy of Sciences,Beijing 100049,China;Xi’an Institute of Surveying and Mapping,Xi’an 710054,China;Shanghai Observatory,Chinese Academy of Sciences,Shanghai 200030,China)

机构地区：[1]中国科学院国家授时中心,西安710600 [2]中国科学院大学,北京100049 [3]西安测绘研究所,西安710054 [4]中国科学院上海天文台,上海200030

出　　处：《时间频率学报》2024年第1期46-53,共8页Journal of Time and Frequency

基　　金：国家自然科学基金(12073074)。

摘　　要：地球定向参数观测的仿真研究对于其实际测量具有指导意义,根据国内两套甚长基线干涉测量全球观测系统(中国科学院国家授时中心+中国科学院上海天文台)进行组网并对其EOP(Earth orientation parameters)测量能力进行了仿真分析。其中6站组网联测相比于3站组网,EOP总观测量时延数量提高约5倍,该网型测量UT1、PMX、PMY3个EOP分量的精度分别提高了2.3倍、3.0倍和2.6倍。不论是3站网型还是6站网型,EOP观测精度都会随着热噪声水平的升高而降低,但统计分析表明,热噪声水平在70 ps以下时,影响EOP测量精度的主导因素仍为网络的几何构型。对6种5台站组网情况下的EOP精度仿真,并与6台站仿真结果对比,表明当其中的喀什、哈尔滨、三亚3个外围观测站缺失时,会导致PMY测量精度的显著降低。Simulation study on determination of the Earth orientation parameters is of importance for realistic very long baseline interferometry(VLBI)measurements.In this paper,we investigate the capability of Earth orientation parameters(EOP)determinations using two sets of geodetic VLBI systems(NTSC+SHAO)in China.The number of baseline delays of the 3+3 network are increased by about 5 times than the 3-stations network.The measurement accuracy of the EOP components UT1,PMX and PMY are increased by 2.3 times,3.0 times and 2.6 times respectively.Although,there can be seen a correlations between the EOP observation accuracy and the thermal noises of delay,under 70 ps level,the dominant factor affecting the EOP accuracy is still the geometry of the network rather than the thermal noise.To investigate the effects of each stations on EOP determinations,we simulate the performance of 5-station networks and found that the lack of the three outer stations,Kashgar,Harbin and Sanya would significantly reduce the accuracy of the polar motion y component.

关 键 词：甚长基线干涉测量 地球自转 地球定向参数 世界时 极移 

分 类 号：P228.6[天文地球—大地测量学与测量工程]