Warren, if you consider Stanford Research as a producer of a "better GPSDO" you can download their PRS10 manual from their web pages. It contains all the math that you are asking for.
Best regards Ulrich > -----Ursprungliche Nachricht----- > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Im Auftrag von WarrenS > Gesendet: Samstag, 6. Dezember 2008 16:04 > An: Discussion of precise time and frequency measurement > Betreff: Re: [time-nuts] M12 100 Hz vs. 1PPS measurements > > > > Tom, > This is great work and Information to see. > I do think that this will inspire, and make if not a giant > leap, at least a small step to better GPSDO performance. > > 1st question: > Does anyone have or can they tell me where to get a copy of > the actual raw data Tom used for these plots? > http://www.leapsecond.com/pages/m12-adev/ > > The Link on his leapsecond site to the raw data seems to be > missing. www.LeapSecond.com/logs/ - Logbook and raw data (ask) > A request to Tom, so far has gone unanswered. > > 2nd question > Can anyone provide me with the filter formula or algorithm or > any information > regarding that is used by any of the better GPSDO units to > calculate the ECV > Dac output voltage. > > I know about the simple basic 1st order averaging filter > used in some of the units, > and the even more basic but effective over under check to > increment / decrement > an accumulator. BUT it would seem to me there has got to be > filters that give much > better result than either of these available and being used out there. > > Allan deviation (ADEV) and Modified Allan deviation (MDEV) > http://www.mail-archive.com/[email protected]/msg07211.html > > > > > I'm looking for just the basic formula used to process the > phase error data before > being applied to the DAC. I am not looking for anything > secrete or with all the extra > things some use to verify that the data is valid or > appropriate before being applied > or thrown away. > > Thanks, for any information you can provide me. > WarrenS > > ********************** > > > ----- Original Message ----- > From: "Tom Van Baak" <[EMAIL PROTECTED]> > To: "Discussion of precise time and frequency measurement" > <[email protected]> > Sent: Friday, December 05, 2008 12:32 AM > Subject: [time-nuts] M12 100 Hz vs. 1PPS measurements > > > >I know a number of you have been waiting for the results of > this M12 > >experiment. I compared the performance of a 100 Hz output > vs. a 1PPS > >output vs. a 1PPS with sawtooth correction. > > > > http://www.leapsecond.com/pages/m12-adev/ > > > > I think it came out quite well and it may surprise some of you. > > > > /tvb > > > > > > > > > > > > _______________________________________________ > 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.
