[time-nuts] ARRL FMT results

Tom Van Baak tvb at leapsecond.com
Fri Jan 5 17:50:01 EST 2007


> > The other reason the SR and GR corrections must
> > be made in the SV is because they affect the GPS
> > clock frequency; it's a redshift.
> 
> Indeed. The SV is actually slightly low in frequency before lauch, it is set to
> -4.467E-10 below the nominal correct frequency to compensate the gravitational
> potential difference. This is a static compensation which eats up most of that
> effect. This means that the vehicles is set to 10.22999999543 MHz rather than
> the 10.23 MHz we expect them to have in orbit.

By the way, if you want to read the original GPS
paper where this redshift was measured and then
compensated for see:

Initial Results of the NAVSTAR GPS NTS-2 Satellite 
http://www.leapsecond.com/history/Ashby-Relativity.htm#NTS-2
and
http://www.leapsecond.com/history/1978-PTTI-v9-NTS-2.pdf

/tvb




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