"That code, like most ADEV calculations, assumes you have phase data..."
In my case, the phase data wraps at each DAC change. Do I need to unwrap it, or change it to delta values? I haven't read enough about ADEV to get a feel of what I want, or what this group means when someone say ADEV of xx. I suspect that I need phase deltas from sample to sample to get the allan deviation of the phase changes? Since mine wraps, I'm not sure if an ADEV even means anything. Bob >________________________________ > From: Tom Van Baak <[email protected]> >To: Discussion of precise time and frequency measurement <[email protected]> >Sent: Sunday, February 2, 2014 10:23 PM >Subject: Re: [time-nuts] Sample "R" script for ADEV under Linux wanted > > >>I suggest to use the TVB's >> http://www.leapsecond.com/tools/adev1.c >> C source and derive your script from it... but first, your GPSDO has >> to put out the time interval error samples or you have a reference and >> a TIC to measure your GPSDO (better this last setup). > >Correct. That code, like most ADEV calculations, assumes you have phase data, >and so it uses the "x" form of >the formula. If the data is period or frequency then you use the "y" form of >the formula. See: http://www.wriley.com/paper2ht.htm for details on both >equations. > >See also: http://leapsecond.com/tools/adev_lib.c which computes ADEV, MDEV, >and HDEV from phase. > >/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.
