[nw_arizona_granny]

It may be a Tesla project.

Bob was showing me that they set up the boxes (about the size of a cereal box, that beamed light and hit something on the modified tractor, so that the farm field could be leveled to a fraction of an inch. It helped with the irrigation water.

Bob Otondo was a good person and it pleased me that he got in at the beginning of a new development.

I do not know if it is still in use and expect he is up in Heaven now.

[Myrddin]

Bob was showing me that they set up the boxes (about the size of a cereal box, that beamed light and hit something on the modified tractor, so that the farm field could be leveled to a fraction of an inch. It helped with the irrigation water.

It's just a LASER leveling device. The "box" has a laser pointer spinning on a turntable. You level the turn table and the pointer traces a perfectly level plane. The modified tractor uses a sensor to lock onto the plane produced by the spinning laser pointer. That gives a constant height reference over the entire field. The constant reference can be used to drive a perfectly level plowing of the surface or an intentional slope to permit drainage in a desired direction.