Rant: Trimble rover kept losing signal on a 2 acre slab layout, almost poured 40 yards off

Last Thursday we were laying out footings for a warehouse slab outside Reno and my Trimble R12 just started dropping corrections every few minutes. The base station was fine, we set it up fresh, but the rover would sit there for 30 seconds then kick back to autonomous mode with a busted elevation. I had to re-shoot a grid point like 5 times before I trusted anything. Since it was sunny and clear, I figured it was radio interference from a nearby tower or some new fence line, so I switched to cellular corrections and that helped a bit, but still got a 3 cm shift on one corner. We ended up using a total station for the critical piers and checked the rover's numbers after lunch, and it was off by 8 inches in the middle of the pad. That would have meant digging a 40 yard pour in the wrong spot if I hadn't double-checked. Has anyone else had their GNSS gear act flaky in open desert with no clear source, and what did you do to lock it down?

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susan818d ago

Yeah I've had my rover lie to me in the wide open too, felt like it was just guessing for fun. Saved the concrete by triple checking with a tape measure and trusting the busted gut over the fancy gear.