Patent ID: 7331115

Claim:
A calibration method for calibrating a compass for use on a vehicle, said method comprising: sampling data points of a magnetic field with a magnetic sensor; determining coordinates for the sampled data points relative to an origin of a coordinate system associated with the vehicle and identifying coordinates of a peak of the Earth magnetic field from the coordinates of the sampled data points; assuming an assumed value of the Earth magnetic field magnitude based on the surface of the Earth where said sampling of the data points is occurring; estimating an origin of an Earth magnetic field from the assumed value of the Earth magnetic field magnitude and the coordinates of the peak of the Earth magnetic field; adjusting the magnetic sensor by applying magnetic biasing to said magnetic sensor based on said estimating in order to offset the estimated origin of the Earth magnetic field to the coordinate system associated with the vehicles; and after said adjusting, displaying an output of the compass and determining coordinates for additional data points wherein an output of the compass may be displayed after identifying one peak of the Earth magnetic field.