Hi On a normal GPSDO holdover spec, you are concerned with the maximum time error over a specified period. Generally it’s going to be a 24 hour holdover, but it can be longer or shorter depending on the application. The good old CDMA spec got out into the 10 to 11 us range at 24 hours. Various OEM’s padded the number to give a bit of wiggle room. The spec typically referred to it as “maximum allowed error”. While a straight(ish) line from zero to max is a typical example, they really didn’t care if it was a second, third, or fourth order wiggle bouncing go either side of zero over the period. Figure 8 in the application note is a pretty good example of this. I *think* what is being asked for is the integral of figure 8 ….which is indeed not something I’ve ever seen named.
Bob > On Apr 20, 2017, at 8:26 AM, Tim Shoppa <tsho...@gmail.com> wrote: > > I looked at AN1279 and other HP Smartclock documents that were written for > the telco holdover specs, and they always put a zero axis on the frequency > offset, but I was surprised that for example fig A4 of AN1279 seems to be > suppressing the zero axis for the time error. So they seemed to be > unconcerned with the integral you speak of. > > Tim N3QE > > > On Thu, Apr 20, 2017 at 1:17 AM, Jim Palfreyman <jim77...@gmail.com> wrote: > >> Folks, >> >> I'm after the formal name of something (if it exists), and this group, if >> any, should know. >> >> Consider a plot of a timing residual vs time. Say a watch against a maser, >> residual=watch-maser. >> >> Now if I now plot the cumulative sum (think integral) of the residual, >> that's going to give me an overall view of how the clock is performing over >> time. (If it helps, think of PID controllers and how they work in the "I" >> part.) >> >> Now if you look at *motion* of an object over time, and you integrate its >> acceleration you get velocity, integrate again you get displacement. >> Integrate again and you get "absement" and again you get "abcity" (I only >> recently discovered these terms). >> >> Does the integral of a timing residual have a name, and does the integral >> of *that* have a name as well? >> >> Any thoughts? >> >> >> Jim Palfreyman >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
