[EMAIL PROTECTED] (Bruce Kling) writes: >Hello,
> >I am currently running GPS as a separate process, independent of NTP and >I am able to achieve microsecond accuracy If I run GPS under NTP as a >reference clock driver will this impact on the accuracy of time in any >way? Thank you. Not sure what you mean. GPS is, in this context a hardware timing process. What do you mean "running GPS as a separate process"? You have a program which reads GPS, or which interrupts whent eh GPS PPS hits. How do you know you have "microsecond accuracy" and what has microsecond accuracy? And what does "impact the accuracy" mean? The GPS PPS can be used to discipline the local lock on a computer using ntp to a few microseconds standard deviation. I have a computer which does that. You can see the results on www.theory.physics.ubc.ca/chrony/chrony.html and look at string, which is a computer running ntp driven by the GPS PPS signal. As you can see the offsets tend to be around 3 usec. (mainly due to clock reading jitter, but also due to the reaction of ntp to thermal fluctuations of the computer.) (Mind you I have written a separate interrupt routine to read the clock on the parallel port interrupt, feeding the info to ntp via the shm refclock, so whether or not the various possible other refclocks do as well or better or worse I have no idea. ) _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
