面向导航增强的低轨星座设计与应用

Design and Application of Navigation-Enhanced LEO Constellations

随着传统产业升级和新兴技术的发展,社会生产和生活对分米级、厘米级的实时精准定位需求日益凸显。低轨卫星轨道高度低、信号强度大、短时间内几何构型变化快,因此应用低轨卫星开展导航增强服务成为研究热点。低轨卫星的增强服务性能依赖于星座的快速组网和设计,低轨卫星星座构型、轨道高度、轨道倾角等是影响其覆盖性能和增强性能的关键因素。全面分析了低轨星座设计的关键要素,包括轨道高度、轨道倾角和单星覆盖性、地面人口密度、空间环境等,在此基础上设计了单构型和复合构型低轨导航增强星座,并进一步分析低轨星座的覆盖性能。结果显示:复合低轨导航增强星座可以实现对全球的连续覆盖,同时满足极地高密度覆盖和低纬度的连续覆盖需求,对北斗导航系统的增强效果明显。

With the upgrading of traditional industries and the development of emerging technologies,the need of real-time accurate positioning in social production and life at decimeter and centimeter levels has become increasingly prominent.Owing to the advantages of low orbital altitude,high signal intensity,and fast geometric configuration change in a short time,the application of low earth orbit(LEO)satellites to navigation-enhanced services has become a research hotspot.The enhanced service performance of LEO satellites depends on the rapid networking and design of constellations,and the constellation configuration,orbital altitude,and orbital inclination of LEO satellites are the key factors affecting the coverage and enhanced performance of the satellites.In this paper,the key factors of LEO constellation design,including the orbital altitude,orbital inclination,single satellite coverage,population density,and space environment,are comprehensively analyzed.On this basis,single and composite LEO navigation-enhanced constellations are designed,and the coverage performance of the LEO constellations is further analyzed.The results show that the composite LEO navigation constellation can realize the global continuous coverage,meet the needs of high-density polar coverage and continuous coverage at low latitudes at the same time,and enhance the performance of the Beidou navigation system significantly.