A vehicle heading correcting apparatus comprising a gyro, an integrating unit for integrating output data of the gyro, a global positioning system receiver, an acquisition unit for acquiring heading data of a vehicle supplied from the global positioning system receiver, a first computing unit for computing...http://www.google.com/patents/US5469158?utm_source=gb-gplus-sharePatent US5469158 - Apparatus for correcting the detected heading of a vehicle
