卫星导航系统功率增强子星座优化设计与性能分析

卫星功率增强技术是提高区域导航信号抗干扰性能的一种有效措施,在卫星导航全星座中优选出卫星数量少、服务性能优的功率增强子星座,是新一代卫星导航系统建设迫切需要解决的问题。因此提出基于卫星数最少准则的功率增强子星座优化设计方法,详细介绍设计流程、数学模型及最优解搜索策略;定义了可用性水平、精度水平和覆盖范围等指标评估功率增强子星座性能;以GPS为例,分别针对覆盖点目标和区域目标两种应用背景进行功率增强子星座优化设计及性能评估。分析结果表明:全球范围内任意目标点进行功率增强需要12～17颗卫星;实现对我国沿海地区的连续覆盖需要18颗功率增强卫星;覆盖整个亚太地区则需要全星座24颗卫星都具备功率增强能力,这样才能满足其连续性和精度要求,此时最优功率增强子星座的服务范围可扩充至全球区域。

Optimal design and performance analysis of satellite navigation system power-enhanced sub-constellation

The power-enhancement technology of GNSS is one of the effective measures to improve the anti-jamming capability of regional satellite navigation signals. How to select power enhancement sub-constellation which has less satellite quantity and better service performance from global constellation is a problem in urgent need to be solved urgently in the construction of modern navigation system. An optimal design method of power-enhanced sub-constellation based on minimum number of satellites was proposed. The design process, mathematical model and optimal solution search strategy were introduced. Availability level, accuracy level and coverage area were defined to evaluate the performance of the power-enhanced sub-constellation. Taking GPS as an example, the optimal design and performance evaluation of power-enhanced sub-constellation was carried out for the application background of covering point target and regional target. The results of simulation show that power enhancement at any target point worldwide requires 12~17 satellites. 18 satellites are needed to achieve continuous coverage to the coastal area of China. And, covering the entire Asia-Pacific region requires full constellation satellite enhancements to meet continuity and accuracy requirements. In this case, the service range of optimal power enhanced sub-constellation can be extended to the whole world.