[time-nuts] Allan Variance

John Miles jmiles at pop.net
Wed Sep 29 22:09:43 UTC 2010

> > Can anyone recommend software to calulate the Allan varaince from a set
> > of data?
> >
> > I have taken many measurements with the SR620 using it's 500 second gate
> > and downloaded the results into Excel.
> >
> > I can use the SR620 itself to calulate the Allan Variance. However, I
> > want to know the Allan Varaince over a 10000 second sample instead of
> > 500 seconds.
> >
> > Hoping to plug the data into software and get the result!!
> John Miles has written some nice software.
> http://www.thegleam.com/ke5fx/timelab/readme.htm
> It is intended to do the measurement direct, so the measurement log
> becomes in the right format.

There's a nicer-looking beta version at
http://www.ke5fx.com/timelab/setup_test.exe as well, which has some
rendering improvements such as antialiasing and window/font resizing.  It
should work with the SR620 in either direct-measurement mode (either
addressable or talk-only), or via File->Import ASCII Phase or Frequency

Also see Ulrich Bangert's plotter program (Google 'DF6JB plotter' for a
link).  It has some data-manipulation features beyond what TimeLab does.

-- john, KE5FX

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