Research of Exponentially Filter in Atomic Time Scale Algorithm

The settings and effects of exponentially filter in the Atomic Time 1(AT1) scale algorithm is researched in this paper. The different effects of time scale algorithm with an exponentially filter or no exponentially filter is discussed. Simulations verified that the exponentially filter makes the result better. Then how to choose the exponential frequency-weighting time constant is discussed. This parameter is determined from the relative levels of white noise and random walk (or flicker) for clock. Different numerical value gives different results. Compared with a series of numerical values, the optimal value of each clock is given in this paper. On the basis of these works, exponentially filter optimized the AT1 time scale algorithm by estimating of the current average frequency of clock. Waveform figures are given and some valuable conclusions are drawn.