Confidence on the Modified Allan Variance And the Time Variance'

This paper presents tabulated factors for calculating confidence intervals for the square root of the Modified Allan Variance and the related Time Variance when the analysis uses full overlapping of the data. Confidence intervals are determined by multiplying factors fiom the appropriate table times sample deviations. These factors have been calculated fiom the equivalent degrees of fieedom (edt) for the five common power law noise types. Closed form expressions for calculating the edffor these variances and noise types have only recently become available for fully overlapped data analysis. We compute the edfusing two different closed form expressions as well as simulations to ensure correctness of the results. We also show the relative advantage of using the modified Allan variance instead of the Allan variance to evaluate frequency or time stability in the presence of white phase modulated noise