M-Local

[Nate The Surveyor]

I Had calculated that coord, from another surveyor's file. And, STAKED it, as a stand alone coord, and found it, in a clearcut! Then, When I set on it, I STARTED to use an autonomous, but at the last second, copied the search coord, which had bogus elev. This allowed me to stake and find stuff.... within a foot... horizontally.... but the VERTICAL component... was the problem... OK, I am re arranging my brain...

 

[Nate The Surveyor]

It would be handy, if we had an alarm, that said the base coord was too far away, to include the elevation.
And, an alarm, 0 elev. detected, it would alarm that too.
Thank you for your help.
That half way makes sense. AFTER dposing it all again, (Later and better data from the orbits) my direct inverse between 406 and 372 are 0.036 ft.
Elev diff is 0.29'. The elev diff seems large.
Also, looking at 407, the dpos solution, and the rtk solution differ more than expected.
This all can be due to that ZERO elev. Perhaps?
Is there a way to "Fix" this observation?
Confound it, I can seem to find a way to break stuff!

Suggestions for this job?

IF a bad elev can mess it up like this, then an alarm on this item seems like a GOOD IDEA.

Thanks

Nate

 

[Matt Johnson]

It would be handy, if we had an alarm, that said the base coord was too far away, to include the elevation.

The deltas from the base coordinate and the autonomous position are already shown in Base/Rover Setup. If they disagree by too much, "too far" is displayed:

 

[Nate The Surveyor]

When the sweat is running in your eyes, and the sun is beating you back, it is possible to miss such an important detail.
I have thought this through, as much as I can, and it seems that there is no fix for the RTK data I shot on that day. It is possible that was displayed. (probable). But, it would be good, if , when you try to USE either a vert that is too far, or a Horizontal Delta, that is too far, that you get a POP UP, where you HAVE to override it's complaint. This way, you are thoroughly notified.
This is not gonna kill me, if it is never done, but, it will happen again, to somebody else, and it seems to be a good idea, if it were HARDER to mess up this important detail.
As I have tried to think it all through, the RTK data of that day, would be un fixable. But, the PPK it could be possible to fix.
Anyway, thanks for all your help.

Nate

 

[Matt Johnson]

I agree that a popup warning would be good and possibly even blocking the ability to start the base should be considered. Vladimir has already fixed the issue in the development version with large shifts distorting coordinates with long baselines.

 

[Nate The Surveyor]

The size of the barrier, should be commensurate with the size of the disaster, that could occur. Since this is an "un fixable" it should have a higher barrier.

N

 

[Matt Johnson]

The size of the barrier, should be commensurate with the size of the disaster, that could occur. Since this is an "un fixable" it should have a higher barrier.

N

You should be able to fix it by adjusting the base station coordinate with the DPOS solution.

 

[Nate The Surveyor]

Well, I did use DPOS, However, there did it get "Re projected" or did it get "Shifted" (Think rotate, and translate).
For small shifts, from Autonomous to DPOS "real", there is not a significant difference. For larger shifts, hmmmm I'm out of my league to quantify it, but the difference is greater.
What I mean, is the relationship between the BASE and ROVER shots, in RTK, stayed the same, did they not? And, since they stayed the same, then the error introduced, is possibly significant. Due to an excessively large shift.

Am I on the wrong track, with my thinking here?

N

 

[Matt Johnson]

Yes the vectors between the base and rover remain the same. I think the error was mostly just introduced in the M-Local coordinates. Your DPOS coordinates agreed within 0.06' horizontally didn't they?

 

[Nate The Surveyor]

Yes. But, to a shot 88 feet away, the PPK differed from the RTK, a POINT IN THE CLEAR, and shot for around 5 minutes, the difference was significant. Maybe around 1.5 feet, but I'd have to look again. I was just worried about it.Point 407, it is.
N