Conrad, post: 371808, member: 6642 wrote: If the 180* difference between the two shots was 4" then the out-of-plumbness would be 2". May not be so obvious to the user.
True...
I use it mostly for horizontal. I'll do some dirt work topo w/it, but have never done vert. layout with it. I just had to go back into an area I've not been in to for over 5 years. Conventional crew tried to do a 1.25 acre boundary but all our old control had been knocked out or badly disturbed by a grader and Lord knows what else. I went in, found some of my old GPS points and re-localized. Worse positional estimate was 0.06', all others 0.03' or less. Checked into about 4-5 other points scattered throughout a 1/2 section (PLSS) and the worst I missed one was 0.04' N. and 0.02' W. I'll take that, especially in this area. Lots are aliquot portions of a section so it takes lots of traversing to compute the boundaries. I'm not losing sleep over 0.04'! I've done anywhere from 20 sec. to 180 sec. observations with little to no difference in positional error from my experience. This entire section was done w/30 sec. observations only on all points, with 1/2 the originals retied a day later w/an additional 30 sec. observation. I was able to recreate our control pretty easily to be honest. I would use it for layout, but most of our stuff is small (houses, parking lots etc.) and the robot/total station seems to work just fine.