I noticed a few threads about false Kband alerts.
Farm equipment, Tractors and probably lots of other large equipment, use Radar to establish their actual ground speed.
Equipment like this can't use readouts from the transmission because they suffer from an effect referred to as "slip" when they pull equipment through the soil.
To get an accurate speed reading, a radar is mounted below the chassis and pointed at the ground.
This setup also allows the operator to calculate the amount of slip so they can decide whether they need to down-shift, etc.