[ntp:questions] National time standard differences
"terje.mathisen at tmsw.no" at ntp.org
Tue Feb 9 20:46:28 UTC 2010
David J Taylor wrote:
> Thanks for the update, Terje and Richard. You must need more digits in
> the NTP billboard display, then! <G>
If you are phk, with hw-assisted pps timing and Rb-based cpu frequency,
then the answer is yes, you do. :-)
> I remember the flying of caesium or other atomic clocks round the world,
> and that folks had to invoke relativistic corrections. Were these better
> than microseconds as well?
With the corrections, yes absolutely, otherwise they wouldn't have
needed to check the clocks in this way.
Before common mode GPS observation became the default method to compare
clocks, they used to use very wide band radio connections, i.e. like one
or more TV channel links running for a long time.
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"
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