[ntp:questions] Accuracy of GPS satellite signal ?
richard.eich at domain.invalid
Fri Jan 26 20:42:28 UTC 2007
rgilbert88 at comcast.net wrote...
> Richard Eich wrote:
> > If I were to set up five or six global locations, each time-
> > synchronized to a local GPS receiver, how much variability would I
> > expect there to be between the time as indicated by the GPS
> > satellites used by each local GPS receiver.
> > I'm happy to click on a link and do my own reading. Just haven't
> > been able to find the right link yet (still looking, though).
> > Thx
> If you are using a GPS TIMING receiver with PPS output, the leading edge
> of the PPS signal should be within about 50 nanoseconds of UTC. How
> accurately your computer can read that PPS signal is another story.
> Note that is extremely important to use a receiver designed for timing
> service; navigation receivers are optimized for navigation rather than
That's an important thing to know and keep in mind...thank you.
> I have experience with only one such receiver, the Motorola Oncore
> M12+T. I use it with a Sun Ultra 10 Workstation and Solaris 8. I get
> microsecond accuracy. YMMV
> It should not matter which satellites your site is using, they all keep
> the same time to within nanoseconds!
Since we're looking for 0.500us accuracy, it sounds like we're in
pretty good shape from the GPS sats to the GPS receiver.
More information about the questions