Hiper V vs Hiper V+10 antenna model with OPUS
I have a Hiper II, which is very similar to the Hiper V, I think. Mine came with a little short stubby 10 cm extension. I thought the measurement for OPUS was the bottom of the mount.
I looked at the antenna calibrations, it looks to me like the only difference should be 10 cm.
got a reply from NGS:
So in theory, TPSHIPER_V+10 used with a 2.000m input height should produce the same result as TPSHIPER_V used with a 2.100m height, correct?
That would be a logical conclusion, however the two calibrations are fundamentally different. The two calibration files (attached) show unique values for the antenna phase center offsets and phase center variations. We would attribute this difference to the "nearfield effect" of the adapter; precisely why NGS offers two separate calibrations.
A more direct comparison would be between two sessions using the appropriate code as the data was actually collected. For example, occupying a point with TPSHIPER_V @ 2.000 meters, then occupying the same point with TPSHIPER_V+10 @ 2.000 meters. In this instance, the solutions should be resolved to the same point and we would hope the heights compared favorably (within the uncertainty of the solutions).
I will be running some additional tests.
How does Topcon handle it?
When you run the two receivers together, do you get the correct answer?
When I mix match an R10 and R8 receiver together using Trimble they work and give me the correct heights, in other words if I locate a point with the R10 base and an R10 rover it gives me the same results for that point as the R10/R8 combo. No difference in height except for expected tiny errors.
When I send a file to OPUS using Trimble I'm allowed to measure three different HI points for the R10 and I don't have to do anymore, I only have to be sure I imputed into the DC the correct measure point. Trimble corrects for OPUS from there.
I don't know if your Topcon software does that but I would look into how they treat heights with different receivers.
There should be a HI imbedded in the data file that will be different from the measure up. The corrected HI for that receiver.
Are you able to compute static files with your Topcon software?
I would see how it treats the HI issue, it does sound like OPUS has a glitch in it's antenna files.
Topcon may be correct while OPUS isn't.
If you run that same file using Topcon software does it also show the .05m difference?
I have access to OPUS, CarlsonGNSS and Star*Net. That's it.