The development of large Low Earth Orbit (LEO) constellations has necessitated advancements in satellite navigation systems to ensure precision and autonomy. A study by researchers at Wuhan University introduces a novel approach that combines inter-satellite link (ISL) data with onboard BeiDou-3 (BDS-3) observations to accurately determine the orbits of both LEO and BDS-3 Medium Earth Orbit (MEO) satellites. This method, published in Satellite Navigation, corrects systematic constellation rotation by referencing the BeiDou Coordinate System, achieving unprecedented centimeter-level precision.
Traditional precise orbit determination (POD) methods for satellite mega-constellations like OneWeb, Starlink, and CENTISPACETM rely heavily on extensive ground station networks, which are not only costly but also limited by geopolitical and geographical constraints. The innovative technique developed by the Wuhan University team leverages ISLs and onboard GNSS capabilities to minimize this dependency, presenting a scalable and efficient solution for real-time applications. By simulating a 66-satellite LEO constellation equipped with ISLs and onboard BDS-3 receivers, alongside 24 real BDS-3 MEO satellites, the researchers demonstrated significant reductions in orbit errors through the application of a Helmert transformation based on rotation angles derived from the BeiDou Coordinate System.
Dr. Kecai Jiang, the study's corresponding author, emphasizes the method's effectiveness in addressing systematic rotation in autonomous constellation orbit determination. Utilizing existing BDS-3 broadcast ephemerides and inter-satellite measurements, this approach enables high-accuracy navigation services without the necessity for post-processed GNSS products or extensive ground infrastructure. This breakthrough not only improves the resilience and scalability of satellite navigation systems but also reduces operational costs, marking a critical advancement in the integration of LEO constellations with existing GNSS systems.
The implications of this research are vast, extending beyond navigation to potentially benefit global communication, disaster response, and precision agriculture. By facilitating more accurate and autonomous satellite operations, the rotation-corrected integrated POD method represents a significant leap forward in satellite technology and its global applications.
