Brooke, See old posting: http://www.febo.com/pipermail/time-nuts/2011-January/053478.html
The effect is too small (~5e-17 over 6 hours) to affect GPS time transfer. /tvb > On Feb 19, 2014, at 8:24 AM, Brooke Clarke <[email protected]> wrote: > > Hi: > > In the video about the Full Moon Curse (that's about measuring the distance > to each of the 5 retro-reflectors on the moon to 1 mm) there's a plot showing > the elevation change in the Apache Point Observatory of about 20 inches peak > to peak. It's exactly the type of change the effects pendulum clocks. > > I asked Tom Murphy if he used GPS to get the elevation plot and the answer is > that it came from the gravitymeter with the use of Love numbers. > http://en.wikipedia.org/wiki/Love_number <- has links to papers on Earth > tides > Also see patent 3449956 and GWR instrument link at: > http://www.prc68.com/I/Pendulums.shtml > > This means that the concrete piers where many Cesium clocks and GPS reference > stations are located are bobbing up and down as if they were on a ocean, > although only tens of inches. > I think there was an earlier post saying this puts a limit (E-16?) on the > ultimate quality of a clock because of it's movement. I wonder if NIST has > one of the GWR gravitymeters on a pier and uses that to discipline their > fountain clocks for the elevation change of the pier or if that's done for > the GPS reference antennas? > > -- > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.end2partygovernment.com/2012Issues.html > > _______________________________________________ > 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.
