方差分量估计的SLR精密轨道综合及精度分析

SLR precise orbit combination and precision evaluations based on variance component estimation

针对目前国际激光服务(ILRS)不同分析中心提供的卫星激光测距(SLR)卫星精密轨道综合问题,该文利用几何加权平均法对各分析中心提供的精密轨道进行综合生成综合轨道,其中各分析中心权重采用方差分量法进行估计,通过各分析中心精密轨道与综合轨道的比较,及该文综合轨道与ILRSA和ILRSB综合轨道对比,评价该文综合轨道精度。结果表明:不同分析中心卫星轨道权重不同,其中德国联邦制图和大地测量局(BKG)和欧空局(ESA)的轨道总体精度较好;通过各分析中心相对综合解的尺度因子的比较分析,发现其尺度因子存在长期的线性项变化;各个分析中心的轨道相对于综合解,对Lageos1/2卫星来说RMS均在2 cm左右,速度RMS为(1.5~3)×10^(-5) m/s, Etalon1/2卫星的位置和速度的RMS变化较大,但总体和权重分布相一致;与ILRSA和ILRSB综合轨道相比,该文的综合轨道在位置上和ILRSA具有较好的一致性,在速度上3种综合轨道的RMS差异大致相同。

Aiming at the problem of precise orbit combination of satellite laser ranging(SLR)satellites provided by different analysis centers of international laser ranging service(ILRS),the method of weighted average was used to make combinations of precise orbit from analysis centers of ILRS to get combined orbits, the weight of each analysis center was obtained use variance component estimation.Then orbits of every analysis center was evaluated based on combined solution,the combined orbits we obtained is also compared with ILRSA and ILRSB orbits which come from ILRS combination centers.The results showed that:each AC had different weight,BKG and ESA’s orbits perform the best.Through the analyzation of each analysis center’s scale w.r.t combined solution,there were long term change in scale;the position RMS of Lageos1/2 was commonly at 2 cm,and(1.5-3)·10^(-5) m/s for velocity,range of RMS of Position and velocity of Etalon1/2 was bigger compared with Lageos1/2,but the RMS distribution was agree with weight.Through the comparison of combined orbits with ILRSA and ILRSB orbits,we found the precision of the combined orbits was more consistent with ILRSA and the RMS differences of velocity of the three kinds of combined orbits were almost the same.