GPS广播星历轨道误差分布模型探讨

Discussion on orbital error distribution model of GPS broadcast ephemeris

针对卫星导航系统监测评估工作中存在的监测非实时、阈值设置不合理等问题,提出依据广播星历参数长期演化特点来确定误差分布模型的方法:选用iGMAS分析中心的广播星历及IGS事后精密星历对广播星历的轨道误差进行研究分析,并对误差分布模型进行假设检验。实验结果表明:IIF和IIR-M型卫星的轨道误差服从正态分布,IIR型卫星的轨道误差服从以2个正态分布组成的双峰分布。

Aiming at the problem that there exist non-real-time monitoring and unreasonable threshold settings in the monitoring and evaluation of navigation system,the paper proposed a method to determine the error distribution model based on the long-term evolution characteristics of broadcast ephemeris parameters：the broadcast ephemeris data from iGMAS Analysis Center and the IGS precise ephemeris data were utilized to analyze the orbital errors of broadcast ephemeris,and a hypothesis test of the error distribution model was implemented.Experimental result showed that the orbital errors of Block IIF and IIR-M satellites would obey the normal distribution,and the orbital error of Block IIR satellite would obey the bimodal distribution composed of two normal distributions.