[ntp:questions] What is the NTP recovery time from 16s step in GPSserver?

Rob nomail at example.com
Wed Oct 31 08:35:26 UTC 2012

David Woolley <david at ex.djwhome.demon.invalid> wrote:
> Kennedy, Paul wrote:
>> I believe the answer to your question is 12.5 minutes.
>> This is the time it takes to receive the full set of 25 almanac frames,
>> which contains the GPSTime/UTC offset (amongst other things).
>> http://en.wikipedia.org/wiki/GPS_signals#Almanac
> I think he knows the time taken for the GPS receiver, which is a lot 
> less than that.  His concern is about how long ntpd takes once the GPS 
> receiver is reporting the correct time.  As noted, ntpd is not specified 
> for this case, so makes no attempt to recover any faster than any other 
> broken local clock case.

The main point is that the local clock is not supposed to be broken.

It worked OK years ago when I implemented it, and I wonder what has
changed now so that it no longer works.  Maybe a change in the Trimble
firmware or a change in gpsd (although I do not see that in the git

When this has been cleared up and fixed, gpsd should not provide time
until the receiver reports the correct values.

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