Hi Tom, Tom Van Baak skrev: > Hi Magnus, > > I've never seen it in print either but I coined the name when I wrote > my ADEV tools. I've found a profound difference in the overlapping > form of ADEV in many cases and so I use it a lot now -- especially > when analyzing the effect of tides on precision pendulum clocks, or > other periodic effects, such as cycling A/C or diurnal effects. > > However almost every technical paper in the past few decades uses > the plain old textbook non-overlapping back-to-back ADEV so my > software tools call the traditional calculation "ADEV" and I call the > overlapped version "OADEV". > > An alternative was to use words "ADEV(normal)", ADEV(overlapped)" > and "ADEV(modified)" but I chose the shorter ADEV, OADEV, and > MDEV instead. "ADEV" and "MDEV" are already standard, and so > "OADEV" seemed to fit. So far no one has been confused, but I can > see your point.
This at least explains the origin of the OADEV name. Many thanks. If you look at the NIST paper that Bruce gave a link for, it makes very clear that the overlapping Allan deviation/variance should be used and that the original Allan deviation/variance should only be used "when necessary". The original form allows for some useful reductions in computation as a form of "quick" processing could be made with factor 2 tau steps. > See the tool page, which includes source code: > http://www.leapsecond.com/tools/adev1.htm I will look at it again, as I recall I have looked at it earlier. Cheers, Magnus _______________________________________________ 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.
