I have been using Magnet Field for about a year now and we have experienced a grade bust with Magnet software when comparing to our foremans Pocket3d software. For some background info:
We give all our foremen a GR3/GR5 base/rover setup that they use on a daily basis on their sites. These bases are setup and localized using survey control, usually provided by the GC we are working for or the hired surveying firm. They are all using Pocket3d, thus we localize all our projects in this software as well. This also makes importing the .gc3 file into our machine control dozers/graders an easy process. Once we localize using the aforementioned process, I import that .gc3 file into my Magnet Field software. I use either a GR5 or a HiPer VR and connect to the foreman's base on site. We check grade on control points that are part of the localization.
After having issues with an elevation difference between softwares before, I spoke with Topcon Support and they told me to change a few settings in my survey configuration within magnet including; legacy mode in the localization screen, transmit as if zero offset antenna, and use relative calibrations. Unfortunately these settings have yet to provide any remedy to the problem.
This past week I marked a road to be milled with cut/fill values only to have the foreman come behind me and tell me he was shooting .10-.15 lower on all my spots. I checked to ensure we were using the same surface and localization and made sure the appropriate settings were on in my config. AFter this happened, I setup some points at our office and did a localization with pocket3d AND Magnet Field both, also alternating between using a GR5 as a base/rover and a HiPer VR as a base/rover. Unfortunately, I still got the same results regardless of the receiver combination. Localizing in magnet field and importing to Pocket3d (as a legacy localization) still provided the same results.
I have spoken to everyone I know of that could help with this issues and the most common answer I'm getting is that Topcon really doesn't know how to fix this issue and their only solution at the moment (after the above mentioned suggestions didn't work) is to change the rod height accordingly to match the grades we are getting in Pocket3d.
If anyone has any experience with this issue or has any guidance I would greatly appreciate it.
You have quite a mix of receivers and software there. But you don't mention what versions. I have seen this a few times appear in your scenario of mixing and matching. Wondering what is different in this project versus your past projects where you didn't identify this issue? Did you recently acquire new to you, used equipment? How are you performing the localizations, in the field or in the office? This sounds basic, but localizations performed in field often mask the underlying problem. Were you using a projection on past projects without this issue? In my experience your issue has existed within your fleet for many years and you only identified it recently. My first-time notice of this problem was in around 2013 and have seen it come up only a few instances since then within my many construction clients. I maybe wrong but in my experience this is caused by an out of date firmware within the receivers. Bring all of receivers up to date.
~LeeGreen.com
Just updated from GR-5s and Hiper V's to Hiper VR and have experianced the same problem. So I did some testing myself. Launch GR-5 on base point using pocket 3D. I used my Hiper VR as Rover and all is well. Launch Hiper VR as Base and used the hiper VR as a Rover and I am about .128 higher. Made sure I was measuring to base on both GR-5 and Hiper VR and not to slant. Still Bust .128 I loaded Magnet field and tried with that software same result. Then I loaded Pocket 3D V 15 Same result. I have come to the conclusion it is a hiper VR issue and not software.
If you could launch a GR-5 on the base point and use your Hiper VR rover to check in on a point and see what if any difference.
That's a software bug - a bad antenna measure-up conversion or phase center offset for one of those antenna types. The conversion takes place in the collector during the base setup dialog, and the APC position is then passed to the base to broadcast.
But is it the VR's offset that is incorrect in Magnet Field? Or in Pocket3D? Or is it the GR-5 or V in either one of those software packages? I'd be looking at my post-processing software to find out what conversion is being applied, and comparing that with the receiver documentation to find out which is incorrect.
You may want to bring that to Topcon's attention. Send an email to professional services.
I've had a few issues with V15 Pocket 3D, do you have the "Relative antenna offset" checkbox selected?
That check box makes a .06' difference in elevation.
Apparently you didn't read my post. I have seen this several times. Topcon is aware of this. This is caused by an out of date firmware within the receivers. Bring all of your receivers up to date. You have narrowed it down to your VR.
