On Sun, Nov 9, 2014 at 12:45 PM, Bob Camp <[email protected]> wrote: > Hi > > The main point is that NTP picks *one* source from among it’s batch of > inputs and uses that. The ADEV of the output can be no better than the ADEV > of the output. >
The statement above is not correct. NTP does not select just one clock. The statement below is correct and is what NTP actually does. If you look at the output from "ntpstat" you might think NTP selects one clock but internally it's not going that. The display is misleading. In the case of an ensemble of clocks combined with a better approach the > ADEV of the output can be better than the ADEV of the best clock in the > group. It's best to read this http://www.eecis.udel.edu/~mills/ntp/html/warp.html In simple terms it searches for consensus range of time where all the error bars of the various clock overlap and then eliminate clocks who d't agree with the consensus. Of those still "in" it figures out and kind of weighted average. I think you could do the same thing. First find the set of 10MHz oscillators who are in phase with each other to within some statistical limit and then you compute the weighted average phase Maybe start with "Clock Select Algorithm". -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
