[time-nuts] frequency stabilty question

Tom Van Baak tvb at LeapSecond.com
Mon Aug 15 16:43:49 UTC 2011


Correct. Some ADEV plots conveniently include error bars so
the effect of sample count on confidence is in your face. The
TSC 5110 does this. See for example:
http://leapsecond.com/pages/gpsdo/log35824v.gif
http://leapsecond.com/pages/gpsdo/log35825v.gif

There are also a number of modern variants on regular old Allan
deviation that improve confidence even given the same sample
count. In some cases the trade-off here is computation time.

/tvb

> Hi
> 
> The "how long can I go?" part of the question goes immediately to "how good
> do I want?". For a good confidence level, you might want 100 samples at your
> longest Tau rather than 5...
> For long Tau, that can indeed get pretty nasty. 100 samples at 10,000
> seconds is a very long time. It is worth keeping in mind when you look at
> most plots. The confidence drops off significantly at the longer Tau. 
> 
> Bob





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