[ntp:questions] Re: GPS signal quality

Brad Knowles brad at stop.mail-abuse.org
Wed Nov 10 19:22:11 UTC 2004


At 2:07 PM -0500 2004-11-10, Richard B. Gilbert wrote:

>  When GPS does work reliably; e.g. when you have a good quality signal from
>  four satellites, your clock can synchronize to within 40 microseconds or
>  better.

	This is why it can be extremely useful/important to use a GPS 
receiver that also includes an OXCO or other type of accurate clock 
that can be disciplined by the GPS signal, so that you can continue 
in a degraded mode while the GPS signal is not available and yet 
still have reasonably good time being delivered to your server.

	One example here would be the Meinberg unit.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.



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