The US-based services work fine with non-local data. I've used them with Australian locations. The IGS network is global so nearby stations in the IGS network are used for the solution. There are non-US services too, like AusPos.
The topic of better antenna coordinates seems to come up now and again. It might be a good cooperative timenuts project to put together a travelling receiver system that could be used to survey antenna positions. With a bit more effort, it could also be used to calibrate delays, where receiver data is being post-processed for time-transfer. Cheers Michael On Fri, 27 Apr 2018 at 8:02 am, Bob kb8tq <kb...@n1k.org> wrote: > Hi > > If you shop for a while on eBay, you can find older L1 / L2 survey > receivers for < $300 and > an antenna that will work for them for < $100. Yes it will take a bit of > heavy duty shopping and > some level of “wait and see”. How well they work and how much of a pain > is associated with > this process ….. who knows. > > Once you have a radio you can get data out of, submitting the files to any > of the free services > in the US is pretty easy. If you are outside the US, you may still be fine > or you may have a tough > time with the data reduction. > > Bob > > > On Apr 26, 2018, at 1:04 PM, Scott McGrath <scmcgr...@gmail.com> wrote: > > > > Swiftnav has a centimeter accurate multi band receiver RTK-585. Its > about 600 bucks minus antenna. > > > > You would need a choke ring antenna to get centimeter accuracy i think > but receiver with a quality timing antenna will provide necessary accuracy > > > > On Apr 25, 2018, at 8:06 AM, George Watson <wat...@sierracmp.com> 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 <t...@leapsecond.com> 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 -- 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. > _______________________________________________ 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.