电离层闪烁对北斗增强系统影响的建模研究

Modeling the effects of ionospheric scintillation on BD augmentation system

电离层闪烁严重影响了北斗及其增强系统的性能.为了评估电离层闪烁影响下北斗系统的可用性,需建立闪烁影响下的北斗及其增强系统性能模型,并进行仿真分析.文章系统地建立了电离层闪烁影响下的卫星导航接收机模型、用户定位算法和系统性能模型,利用电离层闪烁模型给出电离层闪烁分布,利用建立的北斗系统性能影响模型,实现对电离层闪烁影响下北斗增强系统性能的可用性分析.利用上述方法,仿真分析了中国中低纬地区强电离层闪烁影响下北斗增强系统的可用性.结果表明:电离层闪烁将引起用户接收机测量误差的增大,对于中国低纬地区而言,强电离层闪烁影响下,存在系统可用性低于95%的性能严重影响区域,北斗系统性能受影响区域与电离层强闪烁的发生区域具有密切关系.

Ionospheric scintillation adversely impacts Beidou(BD)and its regional augmentation system.Making simulation with scintillation effected BD system performance models is the effective way to evaluate the availability of BD services under scintillation condition.A set of models,including the ionospheric scintillation affected receiver models,user positioning algorithms and system performance models are constructed in the paper.A combination of the scintillation distribution from global ionospheric scintillation model(GISM)and established models make it possible to analyze the system performance of BD and its augmentation system under scintillation condition.Simulation was conducted with the method to assess the service availability of BD augmentation system during the strong scintillation condition.It is found that the errors of receiver measurements will increase,and the system service availability will be degraded to a level of 95% or even less in low latitude areas of China where strong scintillation could happen.The low availability areas correspond closely to the areas existing strong scintillation.