A GPS-based control system for irrigation systems includes a power supply, a
nonvolatile
memory for storing a first set of coordinates corresponding to a reference position
for the irrigation system, circuitry for receiving GPS data and using the data
to generate a second set of coordinates corresponding to a current position of
the irrigation system, and a microprocessor for calculating the azimuth and the
distance between the reference position and the current position using the first
and second sets of coordinates. The control system communicates with a main controller
of the irrigation system to control a function of the irrigation system, such as
stopping, reversing, end gun operation, application rate, or other auxiliary output,
at a selected distance or azimuth value of the current position relative to the
reference position. The control system can be used with either a center pivot irrigation
system or a linear move irrigation system.
