I screwed up my last gps session by forgetting to orient the antenna with the arrow north (it was east).
Can someone more familiar with antenna calibrations tell me how much effect this might have on the elevation measurement in a long session?
I might suspect that the APC height might be different depending on the direction of arrival.?ÿ This is a Trimble TRM14532.00 NONE.
For this one I'm not concerned about the horizontal, which I expect would be the bigger error, because I already planned on a note saying horizontal centering is loose due to tall pole.
This was my first session with a homemade 2.5 meter pole and I don't have the drill down pat yet.?ÿ When putting the antenna on a tribrach it was easy to remember the orientation step.?ÿ
I have never had a vertical error related to antenna orientation. I have had horizontal errors on some early models but nothing significant.?ÿ
You may have an issue during processing if you use blanket centering errors in a network adjustment. This will only show up if your antenna model has a substantial horizontal offset and your work is more precise than normal..?ÿ
In every antenna I have had apart I find a square patch antenna at the heart. I looked at the absolute antenna calibration table for your model and see the values being cyclical as north azimuth varies. I would say any change due to being 90?øoff is imperceptible. The variation is much greater as the observed zenith angle varies, and with long observations that averages out. I would not lose any sleep over it.
I would not comment on a tall pole not being stable as it cycles about the plumb, unless you have a steady stiff breeze.
Paul in PA
