I was out on the baseline checking some total stations this morning, and I set up my GR3's on a couple of the stations.
Inverse results in a horizontal distance between the located points of 918.71Ûª, with the published distance being 918.73Ûª.
That is a VRS network solution, using both GLONASS and GPS, on Tripods and Tribrachs. They were carefully calibrated, leveled and sighted. It is the average of 4 shots each, with each using 100 observations, breaking fix between each shot by obscuring the antenna's view of the sky. Also, the comms with the network was lost between observed stations, resulting in a new VRS for the second station.
No. But I frequently measure between GPS'd points with my total station and simultaneously adjust.
What were your antenna orientations?
That difference could easily be in the antenna orientation or misalignment inside your units.
To check your units and antennas, you do the occupations and then swap the units locations and redo.
Paul in PA
I must be missing something....
The inverse equals 1':45,935'
What is the minimum closure your state allows?
Is your inverse calculated at ground - or grid? Could make up the 0.02'.
Paul in PA, post: 350473, member: 236 wrote: That difference could easily be ...
...just what GPS receivers are capable of. They aren't as good as the total station at pin point relative positioning over short distances. The spec sheet on the SP80, for example, says 8mm + 1ppm for RTK horizontal. That's just about what dmyhill got.
Warren Smith, post: 350486, member: 9900 wrote: Is your inverse calculated at ground - or grid? Could make up the 0.02'.
Ok, I admit it, I did not even do that, I was happy with 0.02'
So, I did apply the combined factor, and...918.73'
(And I used the same unit for both observations, and orientated it the same direction each time.)
0.02 ft is not too bad at all. To get better than that with GNSS you have to use more elaborate procedures in terms of centering measuring antenna heights as well as in computations. Some have been mentioned above. Besides you might also have gotten the same 0.02 ft on a baseline that is five miles long. Static GNSS works much better on longer baselines. I've gotten some incredible results on baselines that were several thousand kilometers long. That's where GNSS really shines.