低轨互联网系统在导航增强服务中的应用前景及挑战

Application Prospect and Challenge of Low Orbit Internet System in Navigation Enhancement Service

近年来卫星通讯技术迅猛发展,低轨互联网系统依托其传输速率高、能够进行大规模远程数据传输的优势,以及低轨星座自身具有的距离地球近、信号落地功率高、空衰小、几何变化快的特点,有望弥补卫星导航系统在播发速率和信号衰减方面的缺陷,解决当前传统卫星导航系统落地率较低和实时精密单点定位(PPP)收敛时间过长的问题。在具体工程实现上,低轨星座可发挥四个方面的作用:一是作为“天基监测站”实现当前全球导航卫星系统(GNSS)的信息增强;二是可作为“导航信息源”,实现信号增强和信息增强;三是作为卫星导航系统的补充和备份,独立维持时空基准;四是实现卫星通信业务与导航增强业务融合建设,在用户层次实现“通导一体”。将低轨互联网星座导航增强总体设计与GNSS运行服务的现状相结合,实现优势互补,可提供覆盖面更广、精度更高、更加稳健的时空服务。本文简要介绍了国内外低轨卫星发展现状,分析了低轨卫星在导航增强方面特别是在广播星历参数设计和低轨星座构型等方面的关键技术,重点讨论了低轨卫星在天基监测信息增强、信号增强和通导一体方面的应用及效益,总结了低轨互联网卫星导航应用发展的前景及挑战。

In recent years,satellite communication technology has developed rapidly.Relying on its advantages of rapid transmission rate and large-scale remote data transmission,as well as the low orbit constellation’s characteristics of proximity to the Earth,high signal landing power,low space decay,and rapid geometric change,the low orbit Internet system is expected to make up for the defects of the satellite navigation system in broadcasting rate and signal attenuation to solve the problems of low ground rate of traditional satellite navigation system and long convergence time of real-time PPP.Regarding specific project implementation,the low-orbit constellation can play four roles.First,as a“space-based monitoring station”,it can enhance the information of current GNSS.Second,it can be used as a“navigation information source”to realize signal enhancement and information enhancement;Third,the low-orbit constellation can be used as the supplement*E-mail:bisan1999@163.com;Tel:15652675699 and backup of the satellite navigation system and maintain the space-time reference independently.Fourth,the integration of satellite communication and navigation services should be realized to realize“integrated communication and navigation”at the user level.By combining the overall design of constellation navigation enhancement in the low-orbit Internet with the current status of GNSS operation services,we can realize complementary advantages and provide broader coverage,higher precision,and more robust time and space services.Firstly,this paper briefly introduces the development status of low-orbit satellites at home and abroad,analyzes the critical technologies of low-orbit satellites in navigation enhancement,especially in broadcast ephemeris parameter design and low-orbit constellation configuration,and focuses on the application and benefits of low-orbit satellites in space-based monitoring information enhancement,signal enhancement and communication integration.The prospects and challenges of applying low-orbit Internet satellite navigation are summarized.