Detection and identification of atomic clock anomalies

When an anomaly occurs in an atomic clock, its stability and frequency spectrum change with time. The variation with time of the stability can be evaluated with the dynamic Allan variance. The variation with time of the frequency spectrum can be described with the spectrogram, a time–frequency distribution. We develop a method that uses the dynamic Allan variance and the spectrogram to detect and to identify the typical anomalies of an atomic clock. We apply the method to simulated data.