[Astronaut3315]

They use centimeter accurate GPS for per-row logged performance data and autosteering on guidance lines. That data’s used for planning, data analysis and to keep the sprayer from trampling over planted crop later in the year.

Older systems follow lines in the field but newer ones also turn at the ends. It allows less skilled operators to do critical operations in the field.

[goda90]

Fields are a set size and shape. They could probably accomplish this with location beacons at the corners of the field if GPS were disrupted long term.

[kotaKat]

> Schwarz says organic farms like his rely heavily on precision farming features, because rows of crops are planted very tightly together to prevent weeds from growing in the spaces between plants. “We used to have markers that would scratch a line in the ground that you could then use to kind of drive by eye,” he said. “Now, we plant so tight in terms of how much the tractor can go side to side and how much the equipment can go side to side that if we aren't absolutely perfect, it just doesn't work. You just physically can’t drive that straight [without guidance]. If you're sitting up there in a tractor seat, you can't steer fast enough or well enough to not kill the crop because we're so tight on clearances.”

Not at the tolerances they're able to drive those hulking beasts under automation, they can't.

[allannienhuis]

I think the suggestion was to use a type of beacon that the automation could lock into for positioning, just replacing the GPS part of the location service, not the driving part. I imagine that would be technically possible, but not worth anyone's time for such an exceptional circumstance.