利用全球卫星激光测距服务系统(ILRS,International Laser Ranging Service)标准点资料对Ajisai卫星进行精密定轨,残差均方根(RMS)优于3cm,得到该星的精密轨道.进而对长春站40cm空间碎片光电望远镜获得的Ajisai卫星的天文定位资料进行精度分析,外符合精度约3″左右.单独利用天文定位数据进行轨道改进,内符合精度优于3″.改进轨道的x、y、z坐标3分量在观测数据覆盖范围内的精度在100m之内.同样地对Jason-1卫星作数据分析,结果和Ajisai卫星精度相当.分析各个弧段的精度变化,发现定标星个数减少,会导致天文定位精度下降.据此提出可以把最少定标星比例作为评定数据质量的参考指标之一.
The precise orbit of the satellite Ajisai is derived from the normal point data of the satellite's laser ranging obtained from the International Laser Ranging Service (ILRS) with a RMS precision better than 3 centimeters. The accuracy of the celestial positioning data is analyzed based on the precise orbit, resulting an external accuracy of 3″. The celestial positioning data is obtained by the 40 cm optical electric telescope in Changchun observatory. The internal accuracy estimated by the orbit determination solely using the celestial positioning data is better than 3″. The accuracy of above orbit is better than 100 m in the J2000.0 coordinate within the observation pass. The data analysis on Jason-1 by the same method yields a similar result as Ajisai. The analysis on the accuracy shows that less reference stars lead to worse celestial positioning accuracy. It is proposed that the proportion of observations with least reference stars can be one of tile quality criteria.