Patent ID: 7437257

Claim:
A method of obtaining a temperature coefficient of an offset of a geomagnetic sensor that comprises a temperature measurement unit and a memory unit, the method comprising: measuring different temperatures of the geomagnetic sensor, which is placed under temperature-control and at zero magnetic field; obtaining a sensitivity property of the temperature measurement unit, with reference to the measured different temperatures; storing sensitivity property data indicating the sensitivity property in the memory unit; correcting the measured temperature of the geomagnetic sensor, measured by the temperature measurement unit, by using the sensitivity property data stored in the memory unit; obtaining a measured value of the geomagnetic sensor, which is placed at non-zero magnetic field, by using the corrected temperature of the geomagnetic sensor; obtaining a temperature coefficient of an offset of the geomagnetic sensor, based on the corrected temperature and the measured value of the geomagnetic sensor; and storing the temperature coefficient of the offset in the memory unit.