基于不同快速星历的GAMIT解算精度分析

Accuracy analysis of GAMIT solution based on different fast ephemeris

由于加米特/格洛布克(GAMIT/GLOBK)软件需要精密星历参与解算,使用延时12~18d的最终星历进行高精度数据处理,不能满足工程建设对于时效性的要求.基于10.71版本GAMIT软件,使用上海天文台、武汉大学、德国地学中心等分析中心发布的多种快速和超快速星历,对全球卫星导航系统(GNSS)控制网进行基线解算和坐标计算,并分别从归一化均方根(NRMS)值、基线精度和待定点坐标精度等方面进行精度分析。结果表明:采用快速星历和超快速星历进行基线解算,结果的NRMS值均优于0.2;快速和超快速星历的解算坐标和最终星历的解算坐标,在X、Y、Z三个方向上差值均不大,最大不超过1mm;国际GNSS服务(IGS)综合分析中心发布的快速星历和星历,相较于其他分析中心的星历产品精度更高,可靠性更好,可以代替最终星历进行解算。

As GAMIT/GLOBK software requires precise ephemeris to participate in the calculation,using the final ephemeris with a delay of 12-18 d for high-precision data processing can no longer meet the requirements of engineering construction for timeliness.Based on GAMIT software version 10.71,this paper uses a variety of fast and ultra-fast ephemerides released by the Shanghai Astronomical Observatory,Wuhan University,German Geoscience Center,and other analysis centers to calculate the baseline and coordinate calculation of the Global Navigation Satellite System(GNSS)control network.Accuracy analysis was carried out in terms of normalized Root Mean Square(NRMS)value,baseline accuracy,and coordinate accuracy of undetermined points,respectively.The results show that the GNSS uses fast ephemeris and ultra-fast ephemeris for baseline calculation results,and the NRMS values are better than 0.2;The differences in the three directions of Y and Z are not large,and the maximum value does not exceed 1 mm;the fast ephemeris and ephemeris released by the International GNSS Service(IGS)Comprehensive Analysis Center are more accurate than the ephemeris products of other analysis centers.The reliability is better,and it can replace the final ephemeris for calculation.