[time-nuts] would an optical primary standard provide any general benefit?

beale beale at bealecorner.com
Tue Apr 3 00:39:08 UTC 2012


Having read this NIST review paper by Thomas E. Parker, "The uncertainty in the realization and dissemination
of the SI second from a systems point of view" http://tf.boulder.nist.gov/general/pdf/2564.pdf

...it seems that any potential improvement in frequency standards (Cs fountain -> optical clocks) will not benefit most time/frequency users, because existing long-range time-transfer methods (TWSTFT and GPS carrier phase) are still limited to at best 2E-16 for 30-day averaging, and there is no generally practical way to improve them currently in sight.  (Laser ranging of satellites being considered not generally practical). Just curious what people think, is this too pessimistic a view, or is it fair to say that having a 10x improved primary standard would not improve stability or accuracy for anyone outside of stabilized optical-fiber distance from such a standard?



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