[ntp:questions] Consumer GPS question

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Wed Feb 7 05:28:56 UTC 2007

>What OS and what kind of receiver?  I've used a handheld on my Windows
>desktop with, um, amusing results.  I used PPS, but the NMEA app couldn't
>tell whether the pulse belonged to the previous second or the upcoming
>second, with the result that I was always one second slow.  Then, of course,
>there's Windows' granularity issues, which assured that even with PPS
>properly configured I wouldn't have been able to get much below 20 ms.
>With a real OS and a dedicated receiver (save the Magellan for hiking), you
>ought to get better results than I did--sub-millisecond, I would think.

With ntp, it's easy to fix the one-second offset.  Use the fudge command
in ntp.conf.  Mine looks like this:
 fudge time1 -1.0         # off by 1.000 Seconds.

These are my opinions, not necessarily my employer's.  I hate spam.

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