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. >
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