Simulation study for commercial time transfer service over geostationary satellite

Over the last twenty years, many technologies and services have come to rely on the GPS for precise timing. Concern is increasing about the wisdom of being reliant on a single timing solution provided by a single country and because of the susceptibility of the GPS signal to unintentional interference, jamming and spoofing. In this paper, we report on further development of our system for timing signal transfer from a precision reference clock using commercial satellite links. The system will have master stations tracking the satellite position and using TWSTFT measurements to synchronize their clocks, transmitting data with the reference timing signal to allow slave stations to adjust the PPS timing signal, compensating for the satellite motion and other uncertainties in the path delay. We will report on a simulation of the full system, including models for the master station clocks and TWTT measurements, using a Kalman filter to track the satellite position.