The compass system of the present invention utilizes an improved calibration routine in which a processing circuit of the compass recalibrates the compass each time three data points are obtained from a magnetic field sensor that meet predetermined criteria. One such criterion is that the three data...http://www.google.es/patents/US6857194?utm_source=gb-gplus-sharePatente US6857194 - Vehicle compass system with continuous automatic calibration
Vehicle compass system with continuous automatic calibration
