Dan Patterson, post: 426774, member: 1179 wrote: That's ridiculous! I guess if they need it better than 2" they better not call that guy again
Seems the original poster of this thread may have a similar understanding or abilities (lack of).
From OP: "so then with this logic, the GPS is useless. you won't layout anything with with GPS but you will use to tie in boundary corners or set main control points. then these points will be out .04 x .04 plus (your logic). so basically i spent $25000 for a rough layout tool."
In my opinion this is product of the GPS sales rep and those buying it just don't truly understand (or test) the product they are buying.
cls5095, post: 426171, member: 6344 wrote: so basically i spent $25000 for a rough layout tool
Yeah, that's about it.
In best conditions, my javad consistently gives +- 0.03'.
That deteriorates to +- 0.08' with canopy. And up to 0.14' in thick canopy. Multiple observations pulls this down to around 0.05.
What kind of gps did the sales guy sell you?
Specs, for rtk, are basicly given, in "good environments". No signs, no buildings, no multipath. All rtk works good, out in the open... It's the obstructions, (multipath) that make it "all go out of spec".
N
I attended a seminar a few years ago on GPS, least squares, and relative position precision. Todd Horton was the speaker, and it was most enlightening.
As most of us know, the total station is the instrument of choice for shorter distances. The GPS is the instrument of choice for longer distances with redundant checks. I forget the distances he talked about, but he had the information to back it up, and it just made sense.
My notes are split between my old outside office, and the home office. I've been slowly moving my study material into the house since merging my solo firm with my new firm. I will try to find the notes and share than information. Hopefully Todd will see this thread and offer his opinions.
