Jbowen, post: 371753, member: 11481 wrote: We use Topcon GR-5's for RTK stakeout (Base and Rover solution). It has performed well for horizontal stakeout but i wouldn't recommend it for vertical/elevations for anything more than TOPO's or other non-critical elevation tasks.
Today we experienced something strange: Has anyone else experienced dissimilar readings depending on which way the user is oriented while performing a point stakeout? ie: stake a point facing north, and then pivot the rod and stake the same point facing south. I was under the impression that it shouldn't matter what orientation the user was facing with a base and rover, but we're getting as much a 4 inches difference between north oriented stakeout vs south on the same point.
No, that shouldn't happen, we do the same thing, and there is no difference.
My friend asked, "Can I lay out a bridge with it." The response? "Brother, I don't think I'd do that."
I saw a contractor try it several years ago... they would've done better using a kaleidoscope and rubber chain!
Jbowen, post: 371753, member: 11481 wrote: We use Topcon GR-5's for RTK stakeout (Base and Rover solution). It has performed well for horizontal stakeout but i wouldn't recommend it for vertical/elevations for anything more than TOPO's or other non-critical elevation tasks.
Today we experienced something strange: Has anyone else experienced dissimilar readings depending on which way the user is oriented while performing a point stakeout? ie: stake a point facing north, and then pivot the rod and stake the same point facing south. I was under the impression that it shouldn't matter what orientation the user was facing with a base and rover, but we're getting as much a 4 inches difference between north oriented stakeout vs south on the same point.
I would say check the plumb on your rod but 4" you would be able to see it's not plumb just by looking at it...does it do the same thing on your control check shots?
Jbowen, post: 371753, member: 11481 wrote: Today we experienced something strange: Has anyone else experienced dissimilar readings depending on which way the user is oriented while performing a point stakeout? ie: stake a point facing north, and then pivot the rod and stake the same point facing south. I was under the impression that it shouldn't matter what orientation the user was facing with a base and rover, but we're getting as much a 4 inches difference between north oriented stakeout vs south on the same point.
Hopefully the bubble on your GPS pole hasn't moved that far since you last checked/adjusted it. How long ago was your last check/adjustment?
Cameron Watson PLS, post: 371783, member: 11407 wrote: I would say check the plumb on your rod but 4" you would be able to see it's not plumb just by looking at it...does it do the same thing on your control check shots?
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.
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.
