参照NRO的CRS和TRS的转换  

THE ROTATIONAL TRANSFORMATION BETWEEN THE CRS AND THE TRS REFERRED TO THE NRO

作　　者：夏一飞[1] 施娟[1] 

机构地区：[1]南京大学天文系

出　　处：《南京大学学报（自然科学版）》1997年第2期230-235,共6页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金

摘　　要：讨论了参照非旋转原点的天球参考系和地球参考系的转换方法，并和经典方法进行了比较。两种转换方法在数值上基本上是一致的，但新的转换方法显示出较好的优越性，它在概念上和实用上更简单，同时指出用甚长基线干涉观测确定地球定向参数的归算中，使用新的转换方法将更合适。The reduction of any observation of a celestial object from the Earth needs a matrix transformation between the Celestial Reference System (CRS) and the Terrestrial Reference System (TRS). The classical transformation refers to the equinox. Since the orientation of the Earth in space as derived from VLBI observations is nearly insensitive to the orientation of the ecliptic, it would be preferable to use a more adequate method. In this paper, the transformation referred to the nonrotating origin (NRO), introduced by Guinot, is discussed. The consistency of the coordinate transformation from the TRS to the CRS referred to the NRO with the classical one referred to the equinox is checked. The new matrix transformation referred to the NRO is conceptually and practically simpler than the classical transformation. The new transformation clearly separates the roatation of the Earth from the celestial and terrestrial motion of the instantaneous equator. This representation is not dependent on the position of the ecliptic. The practical computation of the matrix transformation only requires the knowledge of the two direction cosines of the CEP, instead of the large number of the quantities generally considered. It avoids the artificial separation between precession and nutation. The results show the advantage of using the NRO as the instantaneous origin of the right ascension and the longitude for reckoning the Earth rotation, which is now required by the presently available accuracy in UT1 as determined by VLBI. Such a new representation for the matrix transformation from the TRS to the CRS should be used in the reduction of VLBI observation.

关 键 词：非旋转原点 坐标转换 CRS TRS 地球自转 

分 类 号：P183.3[天文地球—天文学]