[ntp:questions] Ntp-statistics to adjust a radioclock?
Michael L. Semon
mlsemon33 at verizon.net
Sat Mar 31 01:43:31 UTC 2007
Rune Magnussen wrote:
> Is it possible to use the statistics gathered by ntpd to find the optimal
> adjustment for a radioclock?
It depends on where your already-calibrated time sources are located...
...on your local PC: Yes.
...on your LAN: You can get very close.
...on the Internet: Probably not. You will get a result that reflects
the the calibrations of the external servers and their connections to
your PC; but that result may or may not be equal to the various delays
from the radio station to your radio clock and ultimately to ntpd.
> Based on an estimate of the distance to the transmitter and some trial
> and error I have managed to get my clock in pretty good agreement with the
> external servers I use but is there a way to improve that?
> Regard Rune
Yes. Try the scripts from the ntpd source distribution. They are
located in the ./scripts/stats directory. peer.awk and loop.awk are
When calibrating against servers, it's helpful to clear the statistics
files once the reach of every server is 377 and the time offset has
reached zero at least once. After that, the longer that you let ntpd
run, the better the results will be when you run the scripts.
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