The advent of large Low Earth Orbit (LEO) constellations like OneWeb, Starlink, and CENTISPACETM has promised to revolutionize global communications and navigation. However, the precise orbit determination (POD) necessary for these systems has traditionally relied on dense networks of ground stations, which are costly and limited by geopolitical and geographical constraints. A novel method developed by researchers at Wuhan University addresses these challenges by integrating inter-satellite link (ISL) data with onboard BeiDou-3 (BDS-3) observations, significantly enhancing navigation precision for future mega-constellations.
Published in Satellite Navigation, the study introduces a rotation-corrected integrated POD method that simultaneously determines the orbits of both LEO and BDS-3 Medium Earth Orbit (MEO) satellites. This technique corrects the systematic constellation rotation by referencing the coordinate system implied in BDS-3 broadcast ephemerides, achieving centimeter-level precision. Simulations demonstrated that this approach reduces LEO orbit errors from over 20 cm to about 1 cm, offering a low-latency, high-accuracy solution without heavy reliance on ground tracking stations.
The implications of this advancement are profound. By reducing the need for extensive ground infrastructure, the method enables resilient operations in remote or geopolitically constrained regions. Its scalability makes it ideal for next-generation satellite constellations supporting a wide range of applications, from broadband internet to precision agriculture. Furthermore, the ability to achieve uniform accuracy across all satellites, even when only a subset carries GNSS receivers, lowers hardware requirements and operational costs, marking a significant step forward in satellite navigation technology.
Dr. Kecai Jiang, the corresponding author of the study, highlighted the method's potential to tackle the stubborn issue of systematic rotation in autonomous constellation orbit determination. By leveraging existing onboard capabilities and BDS-3 broadcast ephemerides, the technique paves the way for real-time, high-accuracy navigation services in future mega-constellations, enhancing global navigation and timing performance.
