Analysis of Atomic Clock Offset Anomalies Effect on Frequency Stability Estimation

The calculation of atomic clock frequency stability will have a large deviation in estimation of Allan variance due to clock offset anomalies. In this paper, various models of clock offset anomalies are established, and the effects of three kinds of clock offset anomalies such as phase outlier, phase jump, and frequency jump on the atomic clock frequency stability estimation are derived theoretically, followed by experimental verification. The experiment results show that phase outlier is equivalent to the effect of white phase modulation noise, which will lead to deviation in short-term frequency stability estimation; and phase jump is equivalent to the effect of the white frequency modulation noise, which will lead to deviation in both short-term and long-term frequency stability estimation; and frequency jump is equivalent to the sum of random walk frequency modulation noise and white frequency modulation noise, which will lead to deviation in long-term frequency stability estimation. The model established in this paper can provide basis for clock offset anomalies simulation and robust estimation of atomic clock frequency stability.