Oops, units for TDEV are seconds, not nanoseconds! On Wed, 20 Mar 2019 at 7:41 pm, Michael Wouters <michaeljwout...@gmail.com> wrote:
> Hello Dan, > > > As promised here is a comparison of the ZED-F9P and NEO-M8T > sawtooth-corrected PPS. The PPS is measured against a 5071 with standard > tube. Three days of data were used. The 5071 was measured against another > 5071 and I divided the TDEV by sqrt(2). The 5071 data at shorter than 300s > is limited by the counter resolution so I didn't show it. The ZED-F9P is > significantly better than the M8T between 10 and 1000 s but much the same > past 10000s. > > Cheers > Michael > > On Tue, 19 Mar 2019 at 8:02 am, Dan Kemppainen <d...@irtelemetrics.com> > wrote: > >> Bob, >> >> I recalled the plot you posted a few days ago. Nice plot on the F9P, >> BTW. Thanks for posting that. >> >> I don't supposed you happened to be recording a similar plot with a L1 >> only Ublox part at the same time by chance, did you? I think it would be >> interesting to compare a 6T or M8 part to the F9P. (I lack a standard >> good enough to compare them to...) >> >> Thanks! >> Dan >> >> >> >> >> On 3/18/2019 1:00 PM, time-nuts-requ...@lists.febo.com wrote: >> > Message: 2 >> > Date: Mon, 18 Mar 2019 12:26:55 -0400 >> > From: Bob kb8tq<kb...@n1k.org> >> > To: Discussion of precise time and frequency measurement >> > <time-nuts@lists.febo.com> >> > Subject: Re: [time-nuts] Frequency Ensemble >> > Message-ID:<88460ea2-6034-48d1-a77a-fed1f824d...@n1k.org> >> > Content-Type: text/plain; charset=utf-8 >> > >> > Hi >> > >> > There are a variety of GPS devices that put out a PPS. uBlox makes >> some, there >> > are a number of other companies that do so. The PPS comes out modulo >> the local >> > timebase. On a precision part, there is a ?sawtooth correction? message >> that also >> > comes out to further quantify the best guess time of that pulse. >> > >> > Noise wise, even with correction you are lucky to get a one second ADEV >> in the >> > 1 to 2 ppb range with a typical L1 receiver. With a L1 / L2 device like >> the F9P, >> > you might do a bit better than that. >> > >> > The ADEV of your other sources at short tau will be much better than >> the GPS PPS >> > noise. As you average out over long periods, the GPS will win the race. >> > >> > Bob >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.