新参考系的引入对天体测量学的影响

Impacts of the New Reference System on Astrometry

由于观测、参考架、模型、时间尺度精度的不断提高和完善,国际天球参考系(ICRS)被引入使用, IAU 2000年大会决定从2003年起采用新的天球中介极(CIP)、新的天球中介原点(CIO)、新的岁差-章动模型和新的UT1定义等,并定义了新的中介的运动参考架,由此给天体测量学带来很大的影响,天体测量学的内容和实践发生了许多重要的变化。据此,对天体测量学的术语、概念和定义的变化作了描述,并讨论了变化的原因和对天体测量学的影响。新的一套天体测量理论和方法正在变更之中,我们应及时跟上这个领域的发展步伐。

Considering that improved accuracies have been achieved in observations, reference systems, models and time scales, and that the International Celestial Reference System (ICRS) has been introduced into use, the IAU General Assembly of 2000 resolved to adopt a new Celestial Intermediate Pole (CIP), a new Celestial Intermediate Origin (CIO), a new precession-nutation model, a new definition of UT1, and a new intermediate moving reference frame from 1 January 2003, thus it makes a great impact on astrometry. There are many great changes in contents and practices of astrometry. In this paper, the changes of terminology, concepts and definitions are described. The reasons for the changes, the influences on classical astrometry are discussed. A set of new theory and method of astrometry are being modified, we should catch up with development of this field.