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GPS tilt at building corners
Posted by brad-ott on July 22, 2021 at 3:39 pmDoes this really work?
(photos borrowed from the interweb)
shelby-h-griggs-pls replied 2 years, 9 months ago 8 Members · 7 Replies- 7 Replies
Standard survey reply in 3…2…1…
“It depends.“
(Sorry.)
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil PostmanAs to the tilt feature itself, yes, it works. But, that fixed rod antenna is pretty close to a wall blocking half the satellites, so kind of iffy results. In the bottom photo, he could have moved around so the rod was at 135 degrees horizontally from the walls, giving him 270 degrees of access to the sky.
Yes it works, in line with GNSS observation accuracy in general.
@bruce-small
With the full GNSS constellation in play and even losing half the potential satellites may leave you only picking up a dozen or so. So some degradation of the best potential accuracy, but still a plenty good position for a building wall shot.
I suspect it doesn’t work so well if the building corner is an internal return, giving you less than 90 deg. of sky.
Modern buildings not so bad, old buildings where the sides might not be at right angles to each other could be a nightmare as you won’t know if its the building that is skew or just a bad reading. If in doubt also measure each wall with a tape – works wonders when problem solving and a lot cheaper than a return visit (unless all the GPs points are rubbish!).
Yes, but not quite to same accuracy as GNSS alone IMO. I have a Leica GS18i and have tested in open areas so obstructions were not a factor and you do loose a bit of accuracy but depending on what you need may be perfectly fine.
Bigger issue might be multipath and signal blockage, especially if you aren’t using 4+ constellations.
I probably would NOT buy a new receiver that didn’t have the IMU tilt feature, it is valuable enough to be a good tool in right situation.
I bought the Leica Imaging version for same reason, again, it is going to not be quite static GNSS accuracy, BUT for the “minimal” extra cost, there are situations (especially safety situations) where it is invaluable.
Just don’t abuse the features!!!!
SHG
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