FWIW, I have an FTS militarized Cesium that has an accelerometer as part of the OCXO assembly to reduce vibration sensitivity. I'm told -- but can't document -- that it was for the Navy and the idea was to counteract the effects of the ship's guns. FTS engineers had a couple of PTTI articles describing their accelerometer research.
John On Jan 11, 2011, at 1:37 PM, "Tom Van Baak" <[email protected]> wrote: >> While sensitivity to g is an usually specified parameter for crystal >> oscillators, I've been unable to find any indications for atomic clocks, say >> 5071A, or more modestly LPRO. Can anybody point me to any source of info on >> the >> subject? >> Thanks, >> Antonio I8IOV > > Hi Antonio, > > You may find some information on g-sensitivity of rubidium > in old FCS or PTTI papers. There are high-rel rubidium for > the military and space applications, so practical issues of > acceleration and jerk sensitivity have been well researched. > > The other thing you could do is quickly and/or very slowly > turn over a running LPRO and report what happens. Like > what we do with quartz, try it on all three axis. It would be > a fun experiment. > > For a 5071A the frequency shift is gh/c². Earth tides cause > a couple of ten cm change during the day; this change in > local g affects the output by parts in 10^17; way too low to > be detected with a 5071A but getting near to the capabilities > of ion clocks. See: > http://www.nist.gov/pml/div688/clocks_092810.cfm > > For some info on g, tides, and clocks see: > http://www.leapsecond.com/hsn2006/ > > To detect changes in g with a 5071A you can raise the clock > by many meters. For example, g is about 9.808 m/s² at sea > level in Seattle but 1 km up it's closer to 9.805 m/s². A 5071A > runs about 1e-13 faster at 1 km elevation compared to one > at sea level. This is large enough to be measurable. See: > http://www.leapsecond.com/great2005/ > > /tvb > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
