Study and application of real-time frequency deviation adjustment algorithm in establishing a time scale

The time scale algorithm is the key of the establishment of a time scale. This paper proposes a real-time frequency deviation adjustment algorithm. This paper describes the idea and implementation of this algorithm. The algorithm utilize a Kalman filter to estimate the state between the master clock and the other clock, and then adjust the frequency deviation and predict the next time deviation between these two clocks and thus reconstruct the time deviation. The simulated experiments utilize two commercial cesium clocks (Symmetricom -5071A). The principle, idea and performance of the Kalman filter is studied and analyzed. The simulated results indicate that the frequency stability of this reconstructed time deviation is improved effectively when utilizing this algorithm. Since the reconstructed time deviation is the adjusted clock difference between the master clock and the other clock, the conclusion can be got that the frequency stability of the master clock´s time scale is also improved effectively. The algorithm is real-time, and its implementation is with low cost and easy to realize and control, so the algorithm is of high engineering and application values.