Allan Deviation

Allan deviation

Formula

Allan variance

\[\sigma_y^2(\tau)=\frac{1}{2(N-2m)\tau^2}\sum_{j=1}^{N-2m}(x_{j+2m}-2x_{j+m}+x_{j})^2\]

Doc String

allandev(data, rate; [frequency=false], [overlapping=true], [taus=Octave]) Calculates the allan deviation

#parameters:

  • <data>: The data array to calculate the deviation from either as as phases or frequencies.
  • <rate>: The rate of the data given.
  • [frequency]: True if data contains frequency data otherwise (default) phase data is assumed.
  • [overlapping]: True (default) to calculate overlapping deviation, false otherwise.
  • [taus]: Taus to calculate the deviation at. This can either be an AllanTauDescriptor type AllTaus, Decadade, HalfDecade, Octave, HalfOctave, QuarterOctave, an array of taus to calculate at, a float number to build a custom log-scale on or an integer to build a specific number of log spaced points.

#returns: named tupple (tau, deviation, error, count)

  • tau: Taus which where used.
  • deviation: Deviations calculated.
  • error: Respective errors.
  • count: Number of contributing terms for each deviation.
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