基于低轨通信星座的导航增强技术发展概述

在我国北斗三号卫星导航系统全面完成组网建设的背景下,世界卫星导航步入新时代。各卫星导航大国均瞄准更高服务精度、更加多样功能、更加可靠服务,正在着手开展新一代系统建设和技术迭代。随着各国对于大型低轨通信星座的积极开发与广泛部署,应用低轨卫星技术实现导航增强与PNT系统备份能力,因其易与GNSS协同,具有提高全球自主导航精度、拓展全球卫星导航应用市场的巨大潜力而成为研究热点。面向低轨导航增强技术,首先总结了低轨卫星的最新态势,梳理了卫星导航增强服务模式,并详细分析了低轨通信星座导航精度增强及导航信号增强两方面的技术动向。在此基础上,重点针对导航增强频率的兼容互操作、通信/导航信号一体化设计、高动态导航增强信号捕获与跟踪等方面,对低轨卫星导航增强体系未来的发展机遇以及面临的技术挑战进行了展望。此外,还基于美国铱星系统实收采集信号开展了定位服务性能试验分析,结果表明600个历元内收敛定位精度优于100m,相关分析成果可为我国低轨导航增强建设提供参考和借鉴。

Overview of Navigation Augmentation Technology Based on LEO

With the completion of in-orbit construction of China''s Beidou-3 satellite navigation system, the world''s satellite navigation has entered a new era. Major countries in satellite navigation are aiming at providing more accurate, diversified and reliable services, and plan to upgrade technologies and build next generation of GNSS. With the active development and wide deployment of large LEO communication constellation, the application of LEO satellite technology to realize navigation augmentation and PNT system backup capability has become a research hotspot because it is easy to cooperate with GNSS system, improve global autonomous navigation accuracy and expand global satellite navigation application market. For LEO satellite navigation augmentation technology, this paper first summarizes the latest situation of LEO satellites, sorts out the satellite navigation augmentation service mode, and analyzes the technical trends of LEO communication constellation navigation accuracy augmentation and navigation signal augmentation in detail. On this basis, the future development opportunities and technical challenges of LEO satellite navigation augmentation system are prospected, focusing on the compatibility and interoperability of navigation augmentation frequency, integrated design of communication/navigation signal, acquisition and tracking of high dynamic navigation augmentation signal. In addition, this paper also analyzes the performance of LEO based positioning. Simulation results show that the positioning accuracy can achieve the accuracy better than 100m within 600 epochs, which can provide reference for the construction of LEO-NA system in China.