Nick, Comparing the coordinates from the different units, I'm seeing about an 8 ft spread in latitude and about 3 ft in longitude. The elevation is much worse - about a 30 m spread. All units are on the same antenna and splitter.
I used this calculator: http://www.csgnetwork.com/degreelenllavcalc.html These numbers are from self surveys at different times. I will soon be doing a major overhaul of the shelf that holds that equipment. When I do, I'll have all units start a survey at the same time to see how much of a difference it makes. I have three different model GPSDO's, although all of them are HP varients (even the Lucent). Joe Gray W5JG On Mon, May 2, 2016 at 4:21 PM, Nick Sayer via time-nuts <time-nuts@febo.com> wrote: > I haven’t tried, but if you take two GPS receivers of different manufacturers > and feed them the same antenna feed… to what sort of tolerance can you expect > their solutions to coincide? > > I mean, obviously they’re *supposed* to show the same location, but I can > imagine that the math can come up with inexact solutions that may differ > systematically (obviously at low resolution) between different manufacturers. > > Or are those errors swamped by other factors that are not receiver specific? > >> On May 2, 2016, at 2:44 PM, Joseph Gray <jg...@zianet.com> wrote: >> >> Sorry, no Thunderbolts. TVB emailed me to ask if I had one, to make >> the same suggestion. >> >> Joe Gray >> W5JG >> >> On Mon, May 2, 2016 at 11:38 AM, Mark Sims <hol...@hotmail.com> wrote: >>> You could try Lady Heather's precision 48 hour survey. It basically does a >>> weighted average of median filtered fixes over 1 hour time intervals. The >>> median filtering automatically throws outliers out of the data. >>> _______________________________________________ >>> 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. > _______________________________________________ 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.