We just purchased a Trimble R12i GPS unit. It's our first time using the IMU technology (tilt sensor data collection). It's a great tool and frankly, a game changer. However, we also adjust our data with StarNet least squares adjustment software. I was just told Starnet won't adjust measurements that use the IMU. This is a big deal and I'm wondering if anyone has ran into this and has a work-around or more up to date info. I haven't done a field test to verify this yet, but I will be soon. A tech told me that when starnet sees an IMU shot, it computes coordinates at the phase center instead of at the tip of the pole. Obviously this is a huge problem. Anyone have experience with this??
If you're really set on using StarNET, that's going to be a MicroSurvey thing - either they update their conversion utility to apply IMU corrections, or they don't.
There may be a third-party way to transform the JXL files into StarNET input with XSL and custom stylesheets, if you can code and are up for a challenge.
We use StarNET, but only when required by our clients. I like it a lot, but it's really only a network adjustment tool, not a QA/QC and data processing tool. Trimble Business Center is likely the solution here - and it does far more than just adjustments.
It shouldn't take you long to test. Let us now how it works out.
I'm guessing that there is an offset calculation in the raw data, akin to distance and/or angle offsets. The StarNet convertors will need to be updated to deal with these new forms of data.?ÿ Microsurvey can be a bit slow to react to these things. If you have the very latest version of StarNet you will have a better chance of success with it.?ÿ Keep in mind that Microsurvey is a part of the same family of companies as Leica so may not be all hot to support new Trimble features.?ÿ ?ÿ?ÿ
@rover83 Thanks for the reply. Yes, we are set on using StarNet. We adjust everything with it. A typical work flow might be where the field crew starts on assumed coords and begins collecting control and topo. Later, static GPS is observed and ran through OPUS. We then put it all into starnet and let it adjust everything at once. The topo shots are along for the ride (adjustment) so apparently all of the IMU topo shots won't be adjusted correctly.?ÿ
@rover83 Thanks for the reply. Yes, we are set on using StarNet. We adjust everything with it. A typical work flow might be where the field crew starts on assumed coords and begins collecting control and topo. Later, static GPS is observed and ran through OPUS. We then put it all into starnet and let it adjust everything at once. The topo shots are along for the ride (adjustment) so apparently all of the IMU topo shots won't be adjusted correctly.?ÿ
That workflow is easy-peasy to adjust in TBC, and it also allows for QC and blunder checking, not to mention post processing static too, which Starnet does not do. I like StarNet a lot, but there's a reason why manufacturers tailor their software to mesh with their own hardware.
I'm guessing that there is an offset calculation in the raw data, akin to distance and/or angle offsets. The StarNet convertors will need to be updated to deal with these new forms of data.
That's pretty much the case. The IMU readings are embedded in the observation record:
Pretty straightforward formatting, but extracting and making use of the data can be a bit more difficult, which is why I like to let Trimble handle it rather than write my own code. I'll do the coding but it's rarely pretty, and usually less efficient.
@rover83 Proprietary software is always fun to play with...
We don't have TBC nor were we planning on buying it. We came from the world of Topcon and didn't need intermediate steps / software to perform conversions. But then again, we didn't have unique data collection capabilities either. If we can figure out how to get starnet to adjust all the data without buying TBC, that would be nice.
Question... does TBC perform a least squares adjustment? What type of adjustments does it do? Does it have the same ability as starnet to put all types of files (static, levels, rtk, total station) all together into one single adjustment? This part may be more on me to research, but I figured you all might have a quick answer. Thanks for the help!
@rover83 Update:
I just spoke with MicroSurvey (StarNet) and they currently are going to be working on updating their JobXML converter to recognize the tilt sensor data. They said they see pitch/roll/yaw data within the .jxl file but are currently 'disregarding it.' The gentleman I spoke with, James, seems very helpful and willing to figure this out. Until it's resolved, I will be seeking getting TBC to convert to a TDEF file for starnet purposes. I like Starnet and don't want to learn another adjustment software. We're already learning how to use Trimble! Thank you all for the help and perspective.
Microsurvey can be a bit slow to react to these things.
You mean like how there's still no ability to shift elevations up or down on export??ÿ The dialog box for the ground scale coordinate file is pretty much the same as it was in v6 -- you can shift and rotate the horizontal, but you can't shift the vertical to match a site bench mark.?ÿ I asked Ron Sawyer for this at least 20 years ago, but it never made the priority list.
Question... does TBC perform a least squares adjustment? What type of adjustments does it do? Does it have the same ability as starnet to put all types of files (static, levels, rtk, total station) all together into one single adjustment? This part may be more on me to research, but I figured you all might have a quick answer. Thanks for the help!
Least squares isn't exclusive to StarNet...despite what some will claim. TBC (like lots of other commercial software) does perform least squares, in any coordinate system flavor you like, with any combination of static, RTK, NRTK, PPK, levels, or conventional data. Local ground systems, site calibrations, custom coordinate projections, etc. too. Topcon Tools makes use of least squares as well.
Send static files to OPUS through TBC and pull the results directly into a project to update the base position for RTK, or download and process baselines against NGS or private reference stations if you want to use full constellation GNSS and create a static network rather than single points. QC and modify setups, rod heights, codes, attributes, etc. Process F2F linework and export out to CAD, surfaces, etc. etc. StarNet doesn't do that.
As far as whether you need that sort of functionality, it all depends on the type of work you do and whether you want to make the most of your gear or not. I find it easier to work with because it is a one-stop shop for literally every data processing step. It may be overkill for some survey shops. I have access to (and am comfortable using) both - I use StarNet for maybe 1-3% of processing, and TBC for the rest.
I'm trying to wrap my head around getting an R12i without TBC. TBC does so much, even if you don't use it all. Adjustments, yes, even the digital level.?ÿ
You mean like how there's still no ability to shift elevations up or down on export??ÿ The dialog box for the ground scale coordinate file is pretty much the same as it was in v6 -- you can shift and rotate the horizontal, but you can't shift the vertical to match a site bench mark.
It is my judgement that Microsurvey is willing but that they just do not have a lot of resources. What they do have goes in to adding little hamburger helpers that I would probably appreciate more if I was a novice user.?ÿ Your suggestion is a good one. Maybe if more of us ask for it, it will get attention.?ÿ
@jim-frame If you hold the Bench elevation fixed StarNet will use it. I'm not sure I understand what it's not able to do.
StarNet has a function that will translate, rotate, and scale the resultant coordinate file. Useful for creating a file of ground scale coordinates - truncated if you wish it. Or to match a plat basis of bearings, or the like. But it only works in the horizontal plane. There is no corresponding function to translate elevations, which would be useful.?ÿ
If you hold the Bench elevation fixed StarNet will use it. I'm not sure I understand what it's not able to do.
If you fix the elevation of a point that also has an ellipsoid height, it blows up the adjustment unless the geoid height just happens to match the difference between EH and elevation.?ÿ The only workaround that I know of in Star*Net is the alter the EH until you get the desired elevation, but that's dangerous business if you ever have to revisit the project and have it on NAVD88.
What I do now is adjust the elevations in CAD and put a prominent note in the beginning of the .dat file warning that the Star*Net elevations don't match the DWG elevations, but I'm not very happy with that approach, either.?ÿ Coding an elevation translation would be relatively trivial for Microsurvey, which is why this is so frustrating.
Gents,
You should be able to export a TDEF file. The TDEF file is normally exported ground mark to ground mark but use with caution with R12i data because I have had inconsistent results from Trimbles current applications.?ÿ In Trimble Access you should also be able to export a report file ground mark to ground mark however last time I tried it a few months ago it would not actually export the vector measurements ground mark to ground mark as it should.?ÿ I developed a work around in code that exports a synthetic ground mark to ground mark GNSS vector from the *.jxl file and it works with IMU and non IMU data.?ÿ My hope is that Trimble will eventually allow the user to export the *.jxl vector ground mark to ground mark or tilted APC/ARP.
On a related topic - with Leica's new tilting and auto height AP20 pole for total stations they recognized that exporting the?ÿ angle and slope distance measurements to the tilted prism would cause integration issues with many software packages.?ÿ They are exporting what they call a "compensated measurement" HZ-ZA-SD that is computed to be a true vertical measurement from the tip of the pole - of course all the IMU data is stored as well.?ÿ Therefore total station measurements work as before in StarNet. In my mind this is really no different than what I did with the ground mark to ground mark extraction of the *.jxl data which I called the "synthetic measurement" (channeling Kent M.).?ÿ Note that Leica also exports its GNSS vector ground mark to ground mark even with tilted GS18T measurements which again works with StarNet.
BTW - I still consider StarNet my essential LS adjustment tool.
Best regards,
Terry
