Error Analysis and Compensation of Three-axis Strap-down Magnetometers

Three-axis strap-down magnetometers can be used to determine the magnetic heading angle. The magnetometers are widely being employed in vehicle navigation systems. But the precision is enormously affected by additional magnetic field, which is generated by ferrous material and electric devices in the vehicles. In this paper, the basic principle calculating the magnetic azimuth of the body according to outputs of magnetometers is introduced. Then the paper provides the analysis about the error of the magnetic azimuth and the relationship of the error and the interferential magnetic field. The compensation method is also presented and the experimental result shows that the method is effective.