[ntp:questions] prefer in ntp.conf

Jason Rabel jason at extremeoverclocking.com
Thu Jun 14 15:18:53 UTC 2007


Paul,

The post can be found at:

https://lists.ntp.isc.org/pipermail/questions/2007-June/014586.html 

I'm not sure what you mean by the "nmea patch"? My guess is you are trying
to do it all on linux and had to jump through hoops to get it all working.

It's been a while since I looked at the NMEA refclock, but I'm pretty sure
all it looks for is to parse the date/time.

A modified nmea reflock driver could be written so that it also checks
certain sentences to see if the receiver has a 2D/3D fix, or even is just
tracking any satellites. I guess it's not currently in there because not all
receivers output the same sentences by default. Also again a 'better'
receiver will have TRAIM and/or capable of an overdetermistic
single-satellite solution.

Again, what GPS receiver are you using? If you are serious it might be worth
spending a little cash to mount an antenna with a clear view of the sky and
use a receiver that has better features geared toward timing solutions.

Jason


>Jason
>I couldn't find your post on the prefer - it sounds exactly what I am
>finding. Incidently the mnea patch does listen to the nmea data (so you
>could have a totally free standing ntp system. Unfortunately simple GPS
>receivers don't have the capability you mention, hence the need for
>sanity checks.
>
>Paul




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