Right, I thought there should be Trimble's version of a raw data file were all of this information could be seen.?ÿ But like I say I'm not nearly as familiar with Access and (to a greater extent) TBC as I would like, so it's a matter of setting aside time to dive into these softwares.?ÿ And yeah, the error seems to be consistent which is good in that way.
Is there some reason you're shooting your calibration points as observed control points instead of calibration points?
Because when I do the observations, I dont necessarily know whether I will be using a point for calibration or not.
Also I prefer to spin the pole 180 and do a second observation and use the average of the two shots.
This thread (and other similar ones) remind me of an old Jeff Cooper quote:
"Owning a handgun doesn't make you armed any more than owning a guitar makes you a musician."
Just saying.
Loyal
@rover83?ÿ
You can indeed calibrate "on top" of state plane. But you had better be calibrating to values that are close to state plane, or it's going to get all sorts of screwed up.
For instance, if there was a conventional traverse/network done using a state plane value for one or both of the beginning baseline points, it would make sense to start with a state plane system. But if the local ground system is assumed (like 5000/5000 or something), you're going to see some major discrepancies because the calibration is going to warp the hell out of the state plane projected coordinates.
Oh duh, I was way overthinking this.
Yes, JXLs store coordinate system information.
Great, this is nice to have confirmed.
You're likely not doing something wrong, it's more likely they royally screwed up the calibrations before you ever came along. If they supposedly already have a good calibration, why aren't they sticking with that and setting up a template in the office in TBC? Far easier.
Yeah, I might be new to Trimble stuff but I'm pretty sure these problems aren't my doing. ????ÿ
As far as a template... my understanding is that there were 2 field techs for the last couple of years, 1 of which was the calibration guy.?ÿ The company got rid of all of their old survey equipment (Leica) this spring and went all-in with Trimble.?ÿ They had purchased 2 data collectors but the techs mostly only used 1 of them because they ran a 2-man crew.?ÿ I came on board when calibration guy went away and started using the unused data collector so we could run a couple 1-man crews.?ÿ To get this other collector up to speed I started pulling .jxls off the first and that's when I started discovering these problems.?ÿ (Ironically, I've heard the calibration guy thought his brand new TSC7 was broken or buggy because it was giving him "problems" on jobsites.?ÿ In hindsight it was probably just calling out his errors.)
Anyway, yes, once these legacy projects go away and we're able to start projects with the knowledgeable staff and QA/QC procedures that we have in place I think everything will be smooth sailing.
@jimcox?ÿ
Just because you shoot as a point as a calibration point doesn't mean you have to use it though.?ÿ I see Access lets you add a suffix to calibration points as well, so they're automatically named different than your ground coordinate.
The averaging makes sense.
I think some people get confused by the word "calibrate", it seems to imply that the gps equipment will make more accurate measurements or something, when it's been "calibrated".
?ÿ
The static training through Trimble would get the final results, then the final step was to calibrate.?ÿ I questioned the instructor about the reasons for doing such thing, but it was late in the day and he was wanting to leave. I never ever did it, even by 1997 calibration had shown itself to be messy and I wanted nothing to do with calibrating a new set of static control points.
I'm guessing the employee had been through that sort of training.
If there is a SPC file thats calibrated then I would create a new SPC file with a new geoid, export the XYZ from the old file and import those numbers into the new file. Then ckeck the global values, they should match, if not you have problems.
Just curious when you look at the "Job Properties" what does it say??ÿ Does it show you the coordinate system you are in or does it say "Local Site"?
Right, I thought there should be Trimble's version of a raw data file were all of this information could be seen.?ÿ But like I say I'm not nearly as familiar with Access and (to a greater extent) TBC as I would like, so it's a matter of setting aside time to dive into these softwares.?ÿ And yeah, the error seems to be consistent which is good in that way.
That??s exactly what the jxl file is, a readable xml version of the job file.
best way to open is with a good text/xml editor. I use https://www.sublimetext.com/
that recognises all sections, tags and attributes and displays in a nice colored and good readable format. The jxl format is documented byTrimble in a document about making style sheets for custom export.
there are 2 sections in the file: Fieldbook and Reductions.
First will give you all fielddata in chronological order with time stamps, all data about co??rdinate system and calibration included.
Everything is there, even deleted points, modified codes and notes. All data that you can review in Trimble Acces is here.
The Reductions section gives you the Best co??rdinates for each point just as Acces does on the controller for points with multiple observations.
When TBC imports a job file it will first convert to jxl to read it. That file is somewhere in the TBC project directory with an exotic file name, and not an jxl file extenion.
Worth having look!
@rover83?ÿ
First, I have no first-hand knowledge of any of this. I look at a wide range of data from hundreds of years ago as well as current data. From the data and whatever text I can find, I try to deduce the mathematics behind adjustments. Sometimes I deduce incorrectly, so please correct me if I'm wrong.
I remember reading years ago that TBC, when left to its own devices, produced a transvers Mercator projection. Like 5000, 5000, with No Projection/No Datum selected. The link confirms that. Don't know about newer Trimble stuff, but NC is a Lambert state, so I can see the potential for problems with state plane and No Projection/No Datum here.
I'm not really sure as to what "calibrate on top of state plane" means, but I think that NCDOT does something like that. The two files at the link below show an example:
xfer.services.ncdot.gov - /gpsdata/u4007a/
All of the Control Data is changed from the original input to the calibrated coordinate system, so the original data is gone. You can "kinda" check the conversion by using the NCDOT procedure and the point that is calibrated around. What's missing from the hand check is the least squares adjustment. The methodology is here:
Corrections are both welcome and appreciated!
?ÿ
@bstrand?ÿ
The Buggy comment rings true....when people are avoiding the Software upgrades. I work with a few people who flat out refuse to install the Trimble software manager updates.?ÿ Funny thing happened this week. The SX10 refused to operate because the firmware was out of date. Two days wasted and they finally decided to update the firmware, and wow. The damned thing works again.
I secretly update the firmware whenever it is allowed to keep things in the frame of reference for comparison.
You got this.
Out with the superstition and in with math and science!
Nice.?ÿ I tried downloading sublimetext and notepad++ but the company machines are locked down so hard by the IT folks that those options are a no-go.?ÿ Regular notepad seems to work, it just doesn't color code anything.?ÿ Anyway, taking a look at the layout now.
@bstrand?ÿ
No longer the case at my side but i know how you feel.
There might be online xml viewers online, or youR IT-guys might have something official that handles xml in a colorfull way.
@bstrand?ÿ
Then if there's no design, why not start from scratch, and make it all your own??ÿ
Use the old stuff as just a guide as to what's there, etc
Right, that's always an option.?ÿ That takes a little time to get sorted out and do and you know how time = money, especially to the guys in charge. ????ÿ
@loyal?ÿ
Hey Loyal
Drives you nuts if you let it. I don't think I've ever taken the time to thank you publicly for the years of guidance you have given the profession on LDP. I don't think I or my crews have "calibrated" in 20 years because of your posts and answering my emails back in the day. As a result of your willingness to share information our state has?ÿ statewide LDP zones that all our surveyors are happy to use. And we are all set with NGS for the 2022 LDP zones.?ÿ
I really don't know if a value can be placed on the information you have shared over the years.?ÿ
Thank you sir!