I think a big part of the problem is folks not understanding that not all site calibrations are doing the same thing. Geodetic transformations plus horizontal/vertical adjustments can really warp data. It all depends on user input as well as the nature of the local coordinates being calibrated to.
Trimble does a pretty good job of explaining what it is doing depending on user settings:
It looks like NC is doing some version of the top row, but to me it looks like they apply a CSF from a selected point, and then perform the horizontal and vertical adjustments. The report is a bit different from the one TBC spits out, but pretty close.
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@rover83?ÿ
In the NC case, it's difficult to unravel, but it's interesting to note that a different point is chosen for determining the vertical adjustment from the one for the horizontal adjustment. It's also interesting to note the number of points involved in the calibration determination. More than three, not all of the points, but all of the points in the file are ultimately adjusted. Perhaps the original data are preserved somewhere, but not on the given outputs.
Knowing what the black box does with given parameters and selections has to be key to success.
Fascinating stuff.
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but the company machines are locked down so hard by the IT folks that those options are a no-go.
I'm a fan of the Dilbert cartoon strip.
There is an occasional character 'Mordac' - who's job title is 'Preventer of Information Systems'.
Sounds like you have one or more of them on staff...
Trimble gives you three sets of coordinates. The old file will show global L,L,H, Local L,L,H and XYZ coordinates.
From that data you can figure out what happened.?ÿ
When I worked for a different firm, my company bought out and other company with a variety of ongoing small and large projects.?ÿ Our Survey coordinator had me check the control on every single one of them as the PLS for the bought out company did not stay with us long after the acquisition.?ÿ That really ticked me off as I knew the PLS who did the original work and he was a great PLS.?ÿ In the end, I never found more that 0.1' between my work and the original.
Eh, I would do the same thing if I were going to have to stamp & sign work based on those projects.
Unless I was part of the original project effort and personally know how the work was performed, and the control established/adjusted/reduced, I'm going to do my due diligence. Even great surveyors sometimes make mistakes, and I really don't want to have to answer "Yes sir, I relied upon someone else's work without performing any checks whatsoever" if I happen to run with those mistakes and get into a legal bind or backcharged...
@rover83?ÿ
(Russian: ?????ý?æ¥?¥??, ?«?? ?¨¥????ý?æ¥?¥??) Trust, but verify
I think every time my boss buys a company there is some kind of clause saying the pls has to stay a certain number of years minimum. That's the main reason he buys companies these days is to get the surveyor plus some extra staff.?ÿ
@bstrand Ok.?ÿ Hopefully in the calibration you have more than 2 points used for the calibration.?ÿ If you have say 4 or more does the horizontal & vertical values look reasonable.?ÿ If they do then good.
When you had the issues with the TS did you go back to the original job and export the points and then start a new job put the scale at 1 then import the points then used those values to setup the TS (using the shot values not the calc points) and everything seemed to check good.?ÿ If this is what happened then the original job that has the calibration in it isn't solving for using a TS.?ÿ Trimble knows about this issue for awhile and really haven't solved it but I worked with Trimble to do a workaround so that you can use the original calibration job file.?ÿ Let me know if this is what kinda happened so I can help you with the work around.
Sounds like business is great!!!!
I haven't looked at the calibrations in most of these jobs actually.?ÿ I found these errors the first time to these jobsites, figured out a work-around for that day, and haven't been back to any of them.
Like I say, the one job where we did look at the calibration had a 2-pointer.?ÿ The higher-ups are still deciding what to do with that one.
When you had the issues with the TS did you go back to the original job and export the points and then start a new job put the scale at 1 then import the points then used those values to setup the TS (using the shot values not the calc points) and everything seemed to check good.
Yep, that's exactly what happened.?ÿ I don't think it'll be worth trying to fix the problem there though.?ÿ We might have 1 more trip to the site to set final pins and I can just do that with the robot using the job I created.
That's really good to know there's a known bug though.?ÿ I'll keep an eye out for that on other projects, or if I hear word of it happening in other offices.
@rover83 I know the PLS well, he's not only a very long time friend of mine, but a very good surveyor.?ÿ I had followed his footprints several times before the transaction and never found fault.
@350rocketmike If the PLS is not an equal shareholder in the company, that is up to the PLS to decide if he wants to stay on.?ÿ In this particular case the majority shareholder was the PE who established the business that was bought.?ÿ The company that I worked for, the buyer, five PLSs on staff, including myself and our Survey Manager had a personal grudge with the PE who we bought the firm from.?ÿ The only reason he had the surveys disected was to inflict financial harm on the owner to steal his receivables that were still due to him on open accounts.
