Station Elevation for control points
so, something ive been doing is setting up a job with GPS by taking two shots really far apart, (scope of site) then setting a point in the middle that i can occupy with the total station which can see the other two GPS shots, holding one of the GPS elevation, and then station elevation my robot to the point in the middle. this reduces the vert deltas i get using GPS ie: usually my GPS shots can be up to .1 delta ,when using the total station and station elevating i can get them much closer together (like.02)
the problem, when you do a station el it only allows me to either discard or store another. so i click store another, but then in my point manager it shows multiple points with the same # and they have diff coords. this worries me bc how do i know which point # is going to be used for station setups next time i occupy ??
can someone please explain what a station elevation really does and what its appropriate use is?
This appears to be a software specific issue, and most will handle things differently, so you aren't going to get much help until you tell what you are running.
Terminology used sounds like it’s Trimble Access software. Are you sure the multiple coordinates for the same point name aren’t the different face 1 and face 2 observations?
I recommend that you, first, set 3 or 4 points with the GPS rather than just 2. Then use all such points and the resection routine to determine your TS location and orientation. This amounts to a least squares adjustment of the TS position and elevation, best fitting to all of the GPS positions.
If you wish to carry things further you can reshoot the GPS mons with the TS to get positions for them relative to the adjusted TS location. Or, if you have some sort of software available to you to recalc coordinates from raw data, you can repurpose your resection ties to that use back at the office.
I regularly do just this myself and use StarNet to simultaneously adjust the GPS vectors and TS measurements.