[time-nuts] AVAR & Femtoseconds

[jimlux]

Robert Benward wrote:
> Bob
> Boy, you guys are really making me read a lot.  I'm digesting Wiki right 
> now.
> 
> I see tau, but does identifying a tau of 1E-14 allow you to say you are 
> locked to 10fs?  The smallest tau I've seen in my E1938 collection is 1E-1.
> 
> Bob
>  

tau is the time over which the measurement is made, typically 1 second 
or greater.

loosely speaking, the 1e-14 is the average fractional deviation of 
frequency over that time period.