anyone running GPS clocks in Southeastern Georgia?

Owen DeLong owen at delong.com
Fri Jan 21 17:01:10 CST 2011


On Jan 21, 2011, at 1:45 PM, Gary Buhrmaster wrote:

>> NTP isn't going to be the only "ripple".
> 
> Most of the "brand name" GPS NTP solutions have a clock
> with is more than stable enough to survive without GPS
> lock for 45 minutes(*).  Some of the more expensive units with
> temperature controlled oscillators have hold times in the
> many weeks.  My guess is that the NTP ripples will be
> limited to those NTP servers just (or recently) booted
> which have not yet achieved a stable clock state.
> 
> Gary
> 
> (*) This presumes that this test results in loss of signal
>    lock, and not intentionally injected false information.

Loss of lock is a non-issue.

However, the tests they are doing do not necessarily cause loss
of lock. Sometimes, instead, they give you a wrong enough time
to insure that your navigational fix is off by, well, enough to
guarantee that you don't hit what you're aiming at.

Owen





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