I routinely set control points (in relatively clear places) with my Leica 1200, then later occupy those control points with a total station. The typical difference is 0.01 feet, and if I ever saw more than 0.025 feet I would start over. I've also taken the 1200 to a measured baseline and consistently saw the same 0.01 feet. All shots taken five times, one after another and averaged, using a bipod.
A horizontal difference of 0.10 feet means something is wrong with either the equipment or the procedure, or both.
If I used NRTK to set control points, I would hold a "midpoint" between the two network pairs in order to better isolate each ones corresponding error. Both Network Pairs have error (way more error than your total station, but I am neither going to ague for that nor say NRTK does not make good control). I would leave you receiver on the backsights while you are working and post postprocess when back at the office.
so if I set 2 points with my gps rover
Come on, Mr. Jakehart,
As Hi-Staker said, "it depends". You have to be a little more forthcoming with your data. Your statement leaves out a lot of information.
I know nothing about you and how you go about doing what you do, so no disrespect is intended or implied. I do not know anything about the project that you reference nor what specifications the project demands. Maybe a tenth of a foot is more than good enough. I don't know. There is a guy on U-tube doing traverses with sticks in the ground, fer krissakes.
I know the limits of my equipment and my processes and do exactly what you describe on many of the projects I do. I don't have the time, expertise and budget on any of my projects to seek one hundredth of a foot results with my RTK systems. Except maybe that "GPS on BM" point that I did a year or so ago. I expect better than a tenth of a foot, however.
I don't post-process any of my data. I will send data to OPUS and DPOS if I need ties to a particular coordinate system.
So, if are you just looking for some spirited banter on the subject, job well done. Lots of great ideas out there, as usual.
I love this place.
JA, PLS, SoCal
Are you using your GPS in a ground system or a grid system?
Is geodetic distance synonymous with grid distance?
Have you baselined your total station?
Baselined as in checked on a calibration range? In 1994 we used a Topcon GTS-4A for an FDOT project, and we had to check the instrument on a calibration range before starting the project. We removed a side panel on the instrument and set a series of DIP switches to their proper positions.
Mr field hound,
Your questions lead to many other questions.