Low Earth Orbiter (LEO) Navigation Augmentation: Opportunities and Challenges

Abstract

As China’s Beidou satellite navigation system (Beidou system) achieves a primary global coverage, the low earth orbiter navigation augmentation (LEO-NA) technique becomes a hot research topic, since it can easily cooperate with the Beidou system to improve the precision for global autonomous navigation and to extend the application market of the global navigation satellite systems (GNSS). This paper analyzed the demand for and status of the LEO-NA technique, and focused on the in-orbit validation of key techniques for the “Luojia-1A” satellite. It also studied the challenges faced by the LEO-NA system, including interoperability of signal frequencies after navigation augmentation, integrated design of the communication and navigation signals, control and management of the LEO constellations, acquisition and tracking of the high-dynamic augmented signals, and integration with existing GNSS systems. Considering the pressing demand for the LEO-NA techniques, the following suggestions are proposed, including enhancing the top-level design of the LEO-NA system while focusing on the synergy of the LEO-NA and Beidou systems; promoting the integration of the communications, navigation, and remote sensing functions, and building the space-based real-time service system in a stepwise and stratified manner; and planning and constructing the satellite project and the ground infrastructure in an integrated manner.