On Tue, 21 Mar 2017 13:08:56 +0100, you wrote: >On Tue, 21 Mar 2017 13:38:51 +1100 >Hugh Blemings <h...@blemings.org> wrote: > >> This got me to wondering if a Rubidium based standard might do the trick >> - the Efratom SLCR-101s seem readily available for ~USD$200 mark. > >As TvB wrote, a single one will not do the trick. You will need >a stability 1e-14 @1d. IIRC most Rb standards floor out at 1e-12 to 1e-13 >somewhere between 1k and 100k seconds. Even the Super-5065 has a floor >of about 3-4e-14 (unless our friends here improved on this already). > >There will be a few things that you will need to do, if you want to go >with Rubidiums: >1) Stabilize or compensate for environmental effects (temperature, air >pressure) >2) Build ensembles of Rb clocks. >
Hi, Looking back at an old plot I did of a temperature controlled and air pressure compensated LPRO against an M12+T, the Hadamard Deviation of the 1000s averages of the 1PPS measurement was about 5E-14 at 1 day. A large part of that was likely the GPS, so with a better rubidium like an FRK-H in a sealed and temperature controlled enclosure you might be around 1E-14 at 1 day. The bit that I'm not so sure about is the travelling. A long period of movement, vibration, magnetic fields, etc. all adding in could obscure the effects of time dilation. It might be quite possible, although a nearby mountain and a friend with a helicopter would make it a lot easier! Angus. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.