一种单低轨星北斗备份与辅助方法及在轨验证

在低轨卫星上搭载导航载荷,为北斗系统提供有效的备份及辅助性能提升手段,是近年来卫星导航领域专家学者探讨的热点问题。针对全球卫星导航系统信号在恶劣电磁环境下的受扰问题,提出了一种利用单颗低轨卫星实现北斗备份和辅助的方法。北斗备份是指通过单颗低轨星独立为地面用户提供导航服务。北斗辅助是指利用单颗低轨星信号及信息,为地面用户提供北斗辅助信息,增强地面用户的北斗服务性能。低轨星上的导航服务载荷播发信号融合了备份与辅助两种功能。基于该方法设计了北斗备份与辅助一体化载荷和接收终端,并开展了在轨测试验证。在北斗备份模式下,单颗低轨卫星独立定位精度可达703.58m,首次定位时间小于295s;在北斗辅助模式下,低轨北斗备份与辅助一体化终端可实现灵敏度提升12dB,定位精度优于50m。在轨实测验证结果表明,该方法能够为北斗系统提供精度降级的备份与辅助,提升了导航服务在恶劣电磁环境下的可用性,利用单颗低轨卫星辅助北斗可提升12dB抗干扰能力,具有较好的应用前景。

A Beidou Backup and Assistance Navigation Method and On-orbit Test Based on a Single LEO Satellite

In recent years, it is a characteristic problem in the field of satellite navigation to carry navigation payload on LEO satellite to provide effective backup and auxiliary performance improvement means for the Beidou system. In order to solve the disturbance problem of GNSS signal in harsh electromagnetic environment, a method of Beidou backup and assistance using a single LEO satellite is proposed. Beidou backup is to provide navigation services for ground users indepen-dently through a single LEO satellite. Beidou auxiliary means to provide Beidou auxiliary information for ground users and enhance the Beidou service performance of ground users by using single LEO satellite signal and information. The broadcast signal of navigation service payload on LEO satellite combines backup and auxiliary functions. Based on this method, the integrated Beidou backup and auxiliary load and receiving terminals are designed, and the on-orbit test is carried out. In the Beidou backup mode, the independent positioning accuracy of a single LEO satellite can reach 703.58m, and the first positioning time is less than 295s; in the Beidou auxiliary mode, the sensitivity of the integrated terminal can be improved by 12dB, and the positioning accuracy is better than 50m. In-orbit test results show that this method can provide backup and assistance for the Beidou system with degraded accuracy, improve the availability of navigation service in harsh electromagnetic environment, and assist the Beidou system to improve 12dB anti-jamming capability using a single LEO satellite, which has a good application prospect.