High-precision ground simulator for laser tracking of gravity satellite

Inter-satellite laser ranging is a key technology to improve the measurement precision of gravity satellites in future missions. However, it requires a stable laser link between satellites, which would be affected by external disturbances in space and internal couplings of satellite components. This paper presents a dynamic model to describe the tracking error and proposes a high-precision satellite simulator for the validation of inter-satellite laser tracking. Then, the noises of the sensors and actuators are tested to give the theoretical tracking performance of the simulator. Finally, the laser tracking performance is validated through two experiments: fixed-position tracking and motion tracking. The experimental results show that the measured tracking error of the satellite platform is better than 10 mrad/Hz in the fixed-position tracking and 50 mrad/Hz in the motion tracking. Furthermore, the optical platform can reduce the measured tracking error to 80 μrad/Hz in both two experiments. This work provides a theoretical foundation for optimizing laser tracking performance in space missions, and the proposed simulator has demonstrated a potential for mission simulation with laser tracking.