Carrier Phase Based Time and Frequency Dissemination in Satellite-Ground Link

In this paper, we introduce a robust method to conduct time and frequency dissemination over satellite-ground free space. A transmission link is established between one ground station and one geostationary commercial communication satellite to validate this method. Radio frequencies are transferred in the link and the phase noise induced via transfer route is detected in local site and compensated by engaging a phase lock loop (PLL). Under the transmission PLL locking state, we record the remaining phase fluctuation of the received signal, phase data is converted into time information. The result turns to be +/- 230ps time jitter after a total measurement time of 5 days, which is suitable to disseminate time and frequency in satellite-ground link. Transmission stability of the proposed system will certainly get improved with some optimization so the method deserves further study.