1988至1992各年度IERS综合河外射电源表的重新归算

鉴于ＩＥＲＳ综合河外射电源表在建立ＩＡＵ协议天球参考架方面的重要意义和它们的不足之处，本文重新组建了１９８８至１９９２各年度的综合河外射电源表，称之为Ｃａｔ系列表。并依据综合表的组建原理，对重新计算得到的Ｃａｔ系列表进行了检验，结果表明Ｃａｔ系列表克服了ＩＥＲＳ系列表中坐标系不统一的缺点，指向的定义及维持亦较之ＩＥＲＳ系列表有较大程度地改观。比较结果显示，ＩＥＲＳ系列表中部分源的坐标存在毫角秒量级的偏差，各年度综合表的指向与ＩＥＲＳ预期指向亦有不同程度的偏离，个别轴的最大指向偏差至０．６ｍａｓ。同时指出，１９９３年ＩＥＲＳ综合表的指向亦有待讨论。

Recompilation of the Combined Extragalactic Radio Source Catalogues of IERS for Years from 1988 to 1992

Because of the importance of the combined catalogues of IERS to the implementation of a conventional celestial barycentric reference system and the insufficiency of the combined catalogues of the International Earth Rotation Service, the combined catalogues for years from 1988 to 1992 are recompiled in this paper. Methods are briefly discussed and comprehensive examinations are performed to the newly combined catalogues named as Cats. It is shown that the problems of inconsistent coordinate reference system in the IERS catalogues is overcome in the Cat series catalogues. The definition and maintenance of the frame orientation are also improved obviously. Comparisons show that the coordinates of some sources in IERS catalogues are shifted from the expected ones in the X-axis direction at about 0.6 mas in maximum. It is also points out that the orientation of the IERS combined catalogue in 1993 is in question.