oh but RTK is the bomb!!!

Isn't the antenee on the top just a "output" signal to the tractor?

the reciever you have on the "ground" or on the concrete below the tower is the actual "input" side of the location from the sky?  that way the tower moving in wind has nothing to do with the signal sent to the tractor.

You can't recieve your input signal 100 feet above the ground and expect it to be less than one inch on the ground.