Backsight elevation check values

I have noticed this. And I have subtracted a few mm’s off the rod height.

Haven’t ran a closed loop for awhile. Seem to be doing alot of linear alignments lately. Might have to run a small 4 point traverse to compare. What kind of backsight residuals do you commonly see?

That suggests that the problem is in the measurement (ie/ zenith angle) and not the measure ups.

Thanks for all your input. Yes that’s what I’ve been thinking for awhile now. I will have to revisit the check and adjust routine to try and nut this out

Abit of an update guys.

Setup again today, manual sighted everything, VAƒ??s and delta heights were now agreeing in each face. I swapped out the pole and bi pod for a tripod and tribrach. I set the backsight and foresighted in new point. Then rotated the instrument out of its tribrach by 120 degrees. Then reset backsight and re observed foresight. I did this 3 times. When I setup on new foresight point the backsight residuals were 0mm distance, and 0mm in height.?ÿ

I ran a different job file at the same time and observed the backsight and foresight with ATR on, in both faces and didnƒ??t rotate instrument. Backsight residuals for the new foresight were 0mm distance and 2mm in height.?ÿ

I still need to run a level loop around the points to just see how well it matches elevations.?ÿ

Thanks for all the idea and tips shared on the post. Happy Easter?ÿ

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Can't make the link button work.

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