Simultaneous Tracking of Multiple LEO Satellites with Multibeam Phased Array Ground Station

With tens of thousands of low earth orbit (LEO) satellites to be launched in the near future, phased array antennas are envisioned as attractive candidates for future satellite ground stations due to their ability to generate multiple beams via beamforming network, thus supporting multiple satellites simultaneously. Multi-satellite tracking is of great importance for ensuring link quality in satellite communications. However, it is challenging to simultaneously tracking multiple satellites due to orbital perturbations and interference from other satellite signals. In this paper, we propose a multi-satellite tracking scheme for multibeam phased array ground station communication with LEO satellites, which employs direction of arrival (DOA) measurements of satellite signals to aid the satellite dynamics. First, we establish a tracking model that incorporates the relationship between satellite dynamics and measurement angles. Then, we develop a data fusion-based method for multiple LEO satellites by exploiting the DOA measurements of satellite signals using a phased array antenna. The measured DOA data are associated with the target satellite state and processed using an extended Kalman filter (EKF) to enhance tracking accuracy. The updated satellite position is further integrated into a dynamics model to predict angular information, leading to accurate satellite tracking during measurement gaps. Simulation results demonstrate that the proposed tracking scheme achieves a tracking accuracy of within 0.1 degrees in multi-satellite scenarios, significantly improving the tracking accuracy compared to other methods.