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针对北斗全球卫星导航系统混合星座条件下不同星历参数表达方法的性能评估问题,采用了从信息占用量、轨道拟合精度、接收机首次定位时间3个方面统筹考虑的评价方法。针对北斗系统的混合星座构型,比较北斗广播星历16参数和新设计的广播星历18参数的参数定义及用户算法异同,分析了不同星历参数表达所带来的性能变化。仿真分析结果表明,两种星历参数表达虽然都能描述北斗混合星座中的地球同步轨道(GEO)、中间地球轨道(MEO)、倾斜地球同步卫星轨道(IGSO)的卫星轨道特性,但是它们的具体性能有明显的差异,星历18参数的轨道拟合精度比16参数的提高了2~3cm,但其信息表达却多占用了63bit,且接收机首次定位时间多消耗了1.26s。
Aiming at the performance evaluation of different ephemeris parameters under the mixed constellation of BeiDou GNSS, this paper adopts the evaluation method which is considered from three aspects: information occupancy, orbit fitting accuracy and receiver first positioning time. Aiming at the mixed constellation of BeiDou system, this paper compares the parameters of BeiDou broadcast ephemeris 16 parameters and the newly designed broadcast ephemeris 18 parameters and the user algorithm, and analyzes the performance changes caused by different ephemeris parameters. The simulation results show that although the expressions of the two ephemeris parameters can describe the satellite orbital characteristics of the GEO, MEO and IGSO in the Beidou mixture constellation, The performance of the ephemeris 18 parameters is improved by 2 ~ 3cm compared with the 16 parameters, but the information expression takes up 63bit more, and the receiver takes more time to locate for the first time by 1.26s.