面向飞行器自主导航的铱星/星链星座覆盖性及可见性分析

针对低轨星座机会信号导航中单星座构型和可见星数无法同时满足高精度、高可用性的难题，基于铱星、星链轨道参数，建立了单星座和混合星座模型，探究了各个星座覆盖重数、覆盖率及飞行器对上述星座的可见性。研究结果表明：飞行器可见星数随飞行高度增加而减少，随飞行器最小观测仰角增大而减少，星链和铱星的融合可显著增加纬度60°以上区域可见星数。铱星对全球不同纬度、不同时间具有100%全覆盖；星链目前覆盖区域向两极拓展，对全球覆盖重数最大为56,最小为0,未实现全球不同纬度、全时段100%的覆盖率，但中国区域星链覆盖率均优于美国区域。星链和铱星的混合星座使全球覆盖重数优于10,不同纬度、不同时间覆盖率达到100%,显著优于单星座。

Coverage and Visibility Analysis of Iridium and Starlink Constellations for Autonomous Navigation of Aircraft

This paper focuses on the challenges of the configuration of a single constellation and the number of visible stars cannot simultaneously meet the requirements of high accuracy and high availability in low orbit constellation opportunistic signal navigation. Based on the orbital parameters of the Iridium and the Starlink, this paper established single constellation models and hybrid constellation models, explored the coverage multiplicity, the coverage rates for each constellation, and the visibility of aircraft to the aforementioned constellations. The research results indicate that the number of visible satellites during aircraft flight decreases with the increase in flight altitude and decreases with the increase in flight angle of elevation. The fusion of the Starlink and Iridium constellations increases the number of visible satellites during aircraft flight at different latitudes, especially in areas above 60 degrees of north latitude. Iridium achieved 100% full coverage at different latitudes and time around the world. Since its launch, the coverage area of Starlink satellites has gradually expanded towards the North and South poles, and the coverage rate has gradually increased. The maximum coverage multiplicity of Starlink in the world is 56, and the minimum coverage multiplicity is 0. And Starlink has not yet achieved 100% coverage rate at different latitudes and throughout the entire time. But the coverage rate of Starlink in China region is better than that in the United States. The fusion of Starlink constellations and Iridium constellations helps the global coverage multiplicity be greater than 10, with a coverage rate of 100% at different latitudes and times, significantly superior to a single constellation.