Closed Loop Traverse
Quick informal poll: When running a closed loop traverse, you either:
A) Traverse counter clockwise, measuring the interior angles
B) Traverse clockwise, measuring the exterior angles
C) Do not really care, as long as it closes
Thank you in advance, Scott
C. I hardly ever run a closed loop traverse, per se. I measure networks and LS adjust. If a closed loop happens it's incidental.
C - direction is unimportant.
I don't do that anymore, but when I did only the circumstances mattered. Basically, what is the best most efficient way to run the traverse, clockwise or counterclockwise are irrelevant. Possibly that's an old rule connected to describing land clockwise. I always try to write descriptions clockwise, but there's no real reason to do it that way beyond convention and habit.
I always measure horizontal angle right (HAR) regardless of the direction I am travelling.
Like Norman said these days I would take my observations from a network perspective and dump it all into Starnet. Though last year as I was getting started with a new employer, before I had my software sorted out, I long handed a traverse table and applied a compass rule adjustment for old time's sake.
D) - Do it all in terms of Azimuths
Nice poll. So many years ago we ran azimuths and ran counter clockwise so we turned internal angles but azimuths. This made us dummy folks in the field easier to remember N-2. X 180 formula. But we got smarter and realized we could still find a way to run clock and figure our internal angle vs closure and still check the azimuth closure. However it truly doesn’t matter for the math. Now as others have stated I set up networks and perform least squares. It gives you flexibility and also forces more redundancy if done correctly which gives me higher confidence in the overall control of any site.
Every surveyor in our area that I know of turns angles to the right.
Before I had robots turning "sets", I would turn what we called "horizons". Accumulate angles (Topcon lower motion): BS-FS in face 1 (tighten upper, loosen lower, plunge scope) then BS-FS in face 2. Then accumulate the "horizons": FS-BS in face 1 (tighten upper, loosen lower, plunge scope) FS-BS in face 2. All angles turned to the right.
Solve the accumulations and then mean between the angles forward and the horizons. Make sure all the observed angle are within the expected tolerances of the final answer. Rinse Repeat.
So C, and in the past A & B.
In school we went clockwise and turned angles right, but I haven't used a non-robotic total station anywhere I've worked so it's been all sets.
