Hi The problem is that it can / might / could / will create a “dc bias” in the noise. When you filter it, you get a bump rather than zero. If your GPSDO has a 47 ns wide sawtooth, that could be a pretty big bump. There’s no way to know if the bridge is seconds, minutes, or hours wide. You can make a good guess that hours are a *lot* less common than seconds….
If you are after 0.01 ppb (parts per billion), then a 47 ns offset would need to be averaged for about 10,000 seconds if it’s narrow. If it sticks around for 100 seconds you might need to average for quite a bit longer …. Bob On Mar 28, 2014, at 8:15 PM, Eric Williams <[email protected]> wrote: > OK, now I understand the reference, but not the significance in this > context. The sawtooth error is below the resolution of the counter here. > It does produce noise on the transition between capture counts that I am > filtering out, but it should average out over the long-term integration > that I'm using, right? > -- > eric > > > On Fri, Mar 28, 2014 at 4:41 PM, Hal Murray <[email protected]> wrote: > >> >> [email protected] said: >>> I'm sorry, I don't recognize the reference to "hanging bridges". >> >> I guess it was a good thing I mentioned it. Sometimes I feel like a broken >> record. It gets discussed here occasionally. There will be lots of >> comments >> in the archives. >> >> Starter version: >> tvb: Motorola GPS M12+ Sawtooth >> http://www.leapsecond.com/pages/m12/sawtooth.htm >> >> Long version, very good: >> Tom Clark and Rick Hambly: Timing for VLBI >> http://gpstime.com/files/tow-time2009.pdf >> >> >> -- >> These are my opinions. I hate spam. >> >> >> >> _______________________________________________ >> 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. >> > _______________________________________________ > 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. _______________________________________________ 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.
