Hi That sort of accuracy is pretty normal for a survey device. He needs to find a local surveyor who likes to look at stars :). I assume the telescope is not mobile and it’s a one time sort of thing. If he likes to romp around the question becomes how quickly he needs the location information. Post processing is very much part of getting this done. That takes a while (like days .. weeks … months).
Bob > 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.
