Thank you, Tom, so far. Yes, I know that I have to use different formulas, but - of course - I didn't calculate the ADEV curves myself, I let some software do the job, namely Ulrich's Plotter and TimeLab as well. Plotter has a menu item, where you have to check if you deal with phase or frequency data, so I assumed the software would do right.
I am confused. The ADEVs of the phase data are about 10 times better and have a different shape... Volker Am 01.03.2014 12:37, schrieb Tom Van Baak: > Hi Volker, > > Either phase or frequency raw data can be used to generate an ADEV plot, but > you have to use different methods depending on the data type. > > See the two formulas for Allan Variance in: http://www.wriley.com/paper2ht.htm > > Usually we use the "x" form of the formula, where x is an array of phase > samples. But if you have frequency samples then use the "y" form instead, > where y is an array of frequency samples. > > Note you can also convert phase data to frequency data (by differentiating) > and use the "y" form. Or convert frequency data to phase data (by > integrating) and use the "x" form. > > /tvb > > ----- Original Message ----- > From: "Volker Esper" <[email protected]> > To: "Discussion of precise time and frequency measurement" > <[email protected]> > Sent: Saturday, March 01, 2014 3:15 AM > Subject: [time-nuts] ADEV from phase or frequency measurement > > >> Hello dear fellow time-nuts, >> >> I stumbled over a question that may sound stupid to you: >> >> Is the usual ADEV plot the result of a phase or a frequency measurement? >> >> I get totally different results when comparing a phase and a frequency >> measurement of the same source. Or am I doing something totally wrong? >> >> Thanks a lot >> >> Volker > > _______________________________________________ > 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. _______________________________________________ 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.
