A yield monitor is
installed in the clean grain elevator of the combine, and is
electronically connected to a field computer. Every
1 or 2 seconds, the yield monitor sends a signal to the field computer,
providing a measure of how much grain is flowing through the
combine. Grain yield is determined because the computer knows the
distance traveled and the combine header width, thus yield can be
calculated. Pretty clever, huh?
At the same time that the field computer receives a
signal from the yield monitor, a geographic location is recorded in the
computer based on information received from a GPS receiver.