A corner unit guidance control system for use with a corner unit that is part of a center pivot irrigation system includes a primary antenna, a secondary antenna, a receiver, and a controller. The primary antenna and the secondary antenna may receive signals from at least one external positional information source. The receiver may be in communication with the antennas and operable to process the signals to produce position data corresponding to a current position of a wheel and altitude data about the height of the antennas. The controller may be in communication with the receiver and may be programmed to steer the wheel to a heading corresponding to a difference between the current position of the wheel and a point along the path and further programmed to calculate a tilt angle from the altitude data and adjust the heading based on the tilt angle.