IGS分析中心轨道综合算法实现及精度分析

针对IGS轨道综合原理，利用自编算法对IGS各分析中心2014-07~2015-07精密轨道进行综合，获得GPS综合轨道，为我国北斗系统中GEO/IGSO/MEO的轨道组合方法提供参考。结果表明，使用分析中心SIO和不使用SIO综合获得的轨道精度最大三维RMS差异可达4 mm，GPS 1 807周后加入分析中心SIO综合，综合轨道整体精度提高近50%；使用不同的坐标框架统一方法进行轨道综合，精度差异明显，利用单天SINEX旋转参数统一坐标参考框架优于利用ERP参数旋转统一坐标参考框架的方法；最后，使用本文算法计算得到的1 a轨道结果与IGS综合轨道作比较，两者三维差异小于3 mm，RMS均值为1.50 mm，根据各卫星精度因子计算的加权RMS均值为1.16 mm，证明了本文算法的精度和稳定性。

Orbit Combination Algorithm and Accuracy Analysis of IGS Analysis Center

In this paper,based on research from July 2014 to July 2015 from the International GNSS service (IGS) orbit combination theory, GPS combined orbit is computed by an independent algorithm, using the precise orbit of IGS analysis centers. This method has advantages over the combination method of GEO/IGSO/MEO orbit of the Beidou navigation system.According to the experiment, the maximum three-dimensional root mean square(RMS) accuracy difference of combined orbit is up to 4 mm, using the analysis of the Scripps Institution of Oceanography (SIO). The precision of the combined orbit increases nearly fifty percent by using SIO since GPS week 1 807.When using the different methods to eliminate the difference of coordinate reference frame, the accuracy of combined orbit dramatically changed, and the result using the rotation parameter of SINEX is better than that of using that of ERP. Finally, the combined orbit is calculated from 2014 July to 2015 July. Compared with IGS combined orbit, it is found that the three-dimensional difference is less than 3 mm, the mean RMS is 1.50 mm and the weighted mean RMS is 1.16 mm, according to the satellite accuracy code, proving the algorithm’s accuracy and stability.