On 30 Aug, 2012, at 13:14 , Rick Karlquist wrote: >> The other area where a uP is useful is in an environment with high >> vibration. It can correct for acceleration as well as temperature. There > > I've never heard of this being done. Do you have a reference?
I'm not sure how that would be done with a single crystal but I heard a talk by David Allan about a (carefully oriented) array of 6 crystals for which that was done. A Kalman filter which understood the physics of acceleration effects was applied to the output of the 6 crystals to produce a composite clock and, as a side effect, inertial navigation information. This allowed the composite clock to be corrected for g-effects as well as providing the same data that would be output by a conventional, mechanical inertial navigation unit. I think the target application was a drone aircraft, with the clock output ending up at a GPS receiver while the inertial data was used as a fallback if the GPS was jammed and as a sanity check to detect GPS spoofing. This seemed like a nice one-stone-several-birds solution. I have a copy of the powerpoint somewhere, but I've not seen this written down anywhere else. Dennis Ferguson _______________________________________________ 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.
