Recently purchased fc 5000. Did I trial plot ! Measured distances manually in field then shot using DC . We are coming up with a consistent 1% error on all shots. Please help can't figure out where error is coming from.?ÿ
My guess is that you are set up with some grid coordinate system that is not appropriate for the coordinates you are using. It's applying a huge scale factor to your measurements.?ÿ
Another possibility is prism constant.?ÿ ?ÿ
Similarly look out to make sure nothing is getting double corrected.?ÿ Corrected in the instrument and then in the DC after.?ÿ All the number might look correct for your gear but 2x corrected not correct.?ÿ
Also check your PPM or temperature settings on the instrument.
Don't ask me how I ran into these...
Also check your PPM or temperature settings on the instrument.
You can enter barometric pressure and temperature in the FC-5000 and send them to the instrument.
Similarly look out to make sure nothing is getting double corrected.
Earth Curvature and Refraction
https://surveyorconnect.com/community/education-training/earth-curvature-and-refraction/
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Recently purchased fc 5000. Did I trial plot ! Measured distances manually in field then shot using DC . We are coming up with a consistent 1% error on all shots. Please help can't figure out where error is coming from.?ÿ
1% ????ÿ
That would be 1.01 or 0.99 (10,000ppm) or 1 foot in 100 feet!
I can't imagine ANY combination of prism offset. environmental correction, Curvature & Refraction, that would come anywhere close to that.
If in fact you are seeing a consistent 1% variance (bigger or smaller) across varying distances, then it pretty much has to be a SCALE problem in the data collector. In other words, one or more "fields" in the data collector has a VERY messed up value entered into it.
Loyal?ÿ ?ÿ
I can't believe all these wild a$$ guesses are being tossed around when we don't even know what the OP is trying to measure.?ÿ
Is this slope or grade?
It is horizontal distance?
He did a trial plot? What is that? Are we talking about CAD?
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Reminds me of when I get those cryptic emails from construction supers saying nothing other than "Something's wrong with your grades. We need a revised cut sheet ASAP." End email.
These are people just trying to be helpful in a positive way, knowing that new posters vary with the quantity and quality of background information.
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A one percent error is HUGE.?ÿ I don't think you could possibly be that far off between two methods.?ÿ
No grid scale factor is 1% that I've ever seen, however I have seen someone try and push a SPC file from one zone into another zone. For instance you have a DC with Wyoming East Central Zone. You take that DC and go work in the West Zone, you can have a 1% grid scale factor then. Same with UTM zones. This is the only thing I can think of. This would cause the distances to be long. Or take a DC with the Montana Lambert zone stored in it and go work in south Idaho, same problem.?ÿ
we don't even know what the OP is trying to measure.?ÿ
And that's why you have all these wild a$$ guesses...
I know what it is. It's Danish feet.?ÿ?ÿ
From Wikipedia:
The?ÿDanes?ÿstarted with a?ÿsystem of units?ÿbased on a Greek?ÿpous?ÿ("foot") of 308.4 millimetres (1.012?ÿft) which they picked up through trade in the late?ÿBronze Age/early?ÿIron Age.
This is given as an explanation for lost or stolen land in the VI. But the Danish land records from 1 to 2 centuries ago weren't anywhere near accurate to 1%.
we don't even know what the OP is trying to measure.?ÿ
And that's why you have all these wild a$$ guesses...
And it's interesting that we haven't heard back from the OP yet. I for one would be interested if the issues was resolved, and what the problem was.
During my tech support days, it was not uncommon to hear from a field crew that tried to enter a scale factor for all of their conventional measurements because "we're working on state plane". Sometimes they reaaally fat-fingered that scale factor before calling me in a panic.
Fun fact, most of those projects were actually local ground coordinate systems that had been based on state plane, but the coordinate values had not been truncated so they looked like state plane, causing all sorts of problems. Friends don't let friends scale to ground without truncating...