IERS 1996规范在参考系方面的改进
夏一飞 萧耐园
(南京大学天文系 南京 210093)
摘 要
对IERS 1996规范中有关参考系方面作了简单而系统的介绍，重点叙述了
与IERS 1992标准相比IERS 1996规范在参考系方面的主要改进：天球参
考架中的基本源从57颗增加到236颗；动力学参考架采用JPLDE403/LE403历表代替DE200/LE200历表；采用NUVEL NNR--1A板块运动模型代
替NUVEL NNR--1 模型；变更了9个基本常数值；给出了天极坐标的观测和理论间差的经验模型，即IERS
1996 岁差/章动理论；更改了VLBI时间延迟公式中总的引力势表达式，从而与SI秒的规
定相一致。IERS 1996规范还存在一定缺陷，需要进一步改进和提高。
Improvement of Reference System Field in the
IERS 1996 Conventions
Xia Yifei Xiao Naiyuan
(Department of Astronomy, Nanjing University,
Nanjing 210093)
Abstract
IERS 1996 Conventions define the current best standard reference
system. The reference system field is briefly and systematically
described, in comparison with IERS 1992 Standards, the major
improvements made up with IERS 1996 Conventions are presented.
The number of defining source in celestial reference frame increases
from 57 to 236, the planetary and lunar ephemerides are the JPL
DE403/LE403 instead of DE200/LE200, and the NUVEL NNR-1A Model for
plate motion replaces the NUVEL NNR-1 Model, the numerical values of
9 fundamental constants are changed, an empirical model, the IERS
1996 theory of precession/nutation, to be used to predict the
difference in the celestial pole coordinates between observation and
theory is added, the expression of the total potential in the delay
equation is modified to be consistent with the SI second. IERS
1996 Conventions still have some defects. It requires further improvement.
Key words International Earth Rotation Service(IERS)---reference
system
click here for the TWXJZ.