To give an idea about the possible improvement in antenna location available by post-processing the data, I first did a 2 hour self-survey and that put the receiver into position hold mode. Then I collected RINEX data for 16 hours. The post-processed lat/lon/alt values differed around 1/1/3 meters better than the self-survey values (with estimated error ellipses of 0.17/0.15/0.4 meters). Those results were with the "ultra rapid" orbits. It will be interesting to see what they look like when the final precise orbits are available in a couple of weeks. I also need to see how those values compare to Lady Heather's precision survey results.

In my experience, there is little difference between the Final and Rapid, which will be out just about now (for yesterdays observations) Ole On Thu, May 3, 2018 at 6:26 PM Mark Sims <holrum@hotmail.com> wrote: > To give an idea about the possible improvement in antenna location > available by post-processing the data, I first did a 2 hour self-survey > and that put the receiver into position hold mode. Then I collected RINEX > data for 16 hours. The post-processed lat/lon/alt values differed around > 1/1/3 meters better than the self-survey values (with estimated error > ellipses of 0.17/0.15/0.4 meters). Those results were with the "ultra > rapid" orbits. It will be interesting to see what they look like when the > final precise orbits are available in a couple of weeks. > > I also need to see how those values compare to Lady Heather's precision > survey results. > _______________________________________________ > 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. >

On 5/3/2018 9:26 AM, Mark Sims wrote: > Those results were with the "ultra rapid" orbits. It will be interesting to see what they look like when the final precise orbits are available in a couple of weeks. > > I also need to see how those values compare to Lady Heather's precision survey results. FWIW, a dual-frequency PPP run I did late last year has the following uncertainties, when processed with the various IGS precision ephemerides, via AUSPOS:                 longitude           latitude          altitude IGS UltraRapid     0.004m 0.003m            0.013m IGS Rapid          0.004m 0.003m            0.012m IGS Final          0.004m             0.003m 0.012m The computed ECEF coordinates change by 0.003m(X) and 0.001m(Z) between UltraRapid and Final. ...so really not much of a difference between UltraRapid and Final, at least for a dual-frequency survey at my location. *digs through old stuff* Okay, found a single-frequency survey from mid-last-year, processed by CSRS:                 longitude           latitude          altitude NRCan Rapid        0.103m            0.121m 0.253m IGS Final          0.103m             0.121m 0.252m ...not much difference there, either. Both of these were with a roof-mounted antenna and a good skyview, running 24 hours. The first was one measurement every 15 seconds, the latter one measurement per second. (I think for these purposes, one measurement every 15 seconds is more than sufficient and makes the files process *so* much faster). -j