[time-nuts] Noise types and Allan Deviation

[Magnus Danielson]

Tom Van Baak skrev:
> A number of you have asked about Allan deviation recently so
> I thought I'd share this handy one-page chart that shows both
> ADEV and MDEV for the following noise types:
> 
> - white phase
> - flicker phase
> - white frequency
> - flicker frequency
> - random walk frequency
> 
> http://www.leapsecond.com/notes/Exploring_Allan_Deviation.pdf
> 
> It's in high resolution PDF format so if it looks blurry on your
> screen either zoom by 2x or just print it on a laser printer.

You should notice that the phase data looks more or less the same as the 
frequency data two steps down. This is not a coincident, this is because 
there is a derivation/integration (depending on which direction you go) 
relationship between them.

Also notice that the Allan Deviation and Modified Allan deviation is 
shown as Frequency Stability plots, where as if there would have been a 
phase stability plot it would use the Time Deviation (TDEV) meaure. 
There is no TDEV equalent based on ADEV as there is with MDEV, but it 
should be pretty straightforward to convert it in an analogous fashion.

Educational and helpfull. Good work Tom!

Cheers,
Magnus