If it were up to me, I would always double angles when running a traverse.
We were traversing to find and locate a calculated point. I don't understand your second question. Are you asking me if we started the traverse from two known points?
To answer you original question, re-measure the traverse from the beginning. In my experience in many cases traverse busts happen when setting out a line. On numerous occassions, I have measured from the end only to make it to the beginning and find a bad backsight, wrong point number, bad angle turned, bad bearing entered, etc.
Nobody likes to hear it, but the answer to a bust is to run it again. Start at the beginning and do it right- double the angles. With the doubles, you will have no question about the angles.
Now, I am confused here- what you are saying is that the traverse is different from the RTK point and the RTK point matches the office calc?
I'm thinking you need a second RTK point at the end and should traverse tie to that.
But now, I'm thinking about the quality of your localization or calibration, scale factors used???
> The traverse was open-ended. The office calculated the position of the section corner. It was not part of our traverse. I believe there were 5 traverse points. We came off of 2 GPS-derived points. The shortest leg, the first leg, was probably around 100 feet. A single angle was read at each setup. Site conditions definitely played a role here.
It's possible then, that the calculated position is incorrect.
Probably not though (could be though)
I'm guessing that it's angular, due to site conditions and lack of repetition.
At the least a Direct & Reverse Set of angular measurements should have been done, especially in a sideshot traverse.
Oh Well - Live & learn
Or just do what a classmate of mine did years ago, when the instructor asked the class what should be done when a traverse does not close within acceptable tolerances. He blurted out BALANCE IT. - I'm still not sure to this day, if he was serious or not.:excruciating:
When you back site RTK control that is 100ft apart, 6ft is very probable after traversing 1100ft away in 5 setups.
Especially when your setup is in "muck".
I didn't explain the traverse correctly. The RTK control was not 100 feet apart. Actually, it was about 200 feet apart. The second leg was about 100 feet apart.
The RTK position of the section corner was 0.47 feet off from the calculated position. The traverse position was off by about 6 feet.
> Hello,
>
> Has anyone ever heard of running a traverse backwards?
No. I've run 100 leg traverses (road R/W) which close badly where the closing legs were Tellurometer distance and angles back to the IP to car sized targets (20 miles total). Because it was a closed traverse the 400' bust was easily isolated by the bisector of the closing line technique. Based on the math, went to the most likely area and
miserable legs, recovered the control points, reran the angles and it turned out the instrument man instead of reading the vertical circle called on round 2 out the inverse vertical angle based on his mental calculation, saving much time, not.
Sure, today GPS will pick up such egregious errors but there's still a niche for obscured terrain where well done optical observations can outperform.
Someone may have said this already, but if you know you are probably just running one way traverse and not looping back, Do all of your angles while your set over the point once. And always shoot both ways. ie: bs "A" fs "B" then BS "B" and fs "A". Even if you measured from the last point forward, shoot the distance back. You can run your calculations as though you ran it both ways. You can always to the quick test right then and their if the two angles you turned add up to 360.
If it's movinng around in "muck" stay at the point until you get a stable set if at all possible. Turn the angles quickly while backsighting "A" so as to go through minimum movement, and re-stablize the setup if you need to before backsighting "B". We've had unstable setups bad enough that we were afraid to walk around the gun to measure the other direction, so we might have had two people, one pointing to the backsight and the other pointing to the foresight. Better to have the same eye reading both ways, but this can be done.
It's been a long time since I've traversed.
