IERS1996规范在参考系方面的改进

对ＩＥＲＳ１９９６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ＩＥＲＳ１９９２标准相比ＩＥＲＳ１９９６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ＪＰＬ ＤＥ４０３／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

Improvement of Reference System Field in the IERS 1996 Conventions

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.