Digital compasses have an embedded micro controller that subtracts the automobile magnetic field (the distortion) from the stronger earth magnetic fields resulting in a highly accurate compass reading. An electronic compass using magneto-inductive technology is able to electronically sense the difference in the earth's magnetic field from a disturbance caused by external elements such as ferro-magnetic materials and the magnetic field generated by automobile electrical systems. For accurate reading of compass, any distortions of earth's magnetic field should be compensated . Sources of magnetic fields in any automobile include permanent magnets mostly in its audio speakers, motors, electric currents flowing in its wiring either dc or ac, and ferro-magnetic metals such as steel or iron.
The field effects can be compensated by way of calibrating the compass for a defined location in terms of magnetic interference Each calibration method is associated with a specified physical movement of the compass platform in order to sample the magnetic space surrounding the compass. The Hard and Soft iron distortions will vary from location to location within the same platform. Logic Spectra provides the calibration according to the custom needs depending on location and distortions.
