This link seems to provide an overview of Differential GPS and some related techniques.
https://www.e-education.psu.edu/geog862/node/1834 Building a system along these lines from "auction site purchases" and home brewed computer code might be a fun project but one would presumably need an accurately surveyed starting point. Mark Spencer [email protected] 604 762 4099 > On Apr 25, 2018, at 8:06 AM, George Watson <[email protected]> wrote: > > Create your own DGPS? > > Trimble is good at this. > > George K. Watson > K0IW > >> On Apr 25, 2018, at 10:56 AM, Tom Van Baak <[email protected]> wrote: >> >> List -- I had a recent query by a researcher who would like to pinpoint the >> location of his telescope(s) within 0.3 meters. Also (he must be a true >> scientist) he wants to do this on-the-cheap. He may have timing requirements >> as well, but that's another posting. >> >> So I toss the GPS question to the group. Surely some of you have crossed the >> line from precise time to precise location? >> >> How easy, how cheap, how possible is it to obtain 0.3 m accuracy in 3D >> position? >> >> When we run our GPSDO in survey mode how accurate a position do we get after >> an hour, or even 24 or 48 hours? And here I mean accurate, not stable. Have >> any of you compared that self-reported, self-survey result against an >> independently measured professional result or known benchmark? >> >> Do you know if cheap ublox 5/6/7/8 series receivers are capable of 1 foot >> accuracy given enough time? >> >> If not, what improvement would -T models and RINEX-based web-service >> post-processing provide? >> >> It that's still not close enough to 0.3 m, is one then forced to use more >> expensive multi-frequency (L1/L2) or multi-band (GPS, GLONASS, Galileo) to >> achieve this level of precision? If so, how cheaply can one do this? Or is >> the learning curve more expensive than just hiring an survey specialist to >> make a one-time cm-level measurement for you? >> >> Something tells me 1 foot accuracy in position is possible and actually >> easier than 1 ns accuracy in time. I'm hoping some of you can help recommend >> solution(s) to the researcher's question or shed light on this interesting >> challenge. >> >> Thanks, >> /tvb >> >> _______________________________________________ >> 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.
