Magnetic heading compensation method based on magnetic interferential signal inversion

This paper presents a method for compensation of disturbances introduced by near-surface interference sources in the estimation of magnetic heading, based on the inversion of the interference signal. Firstly, magnetometer array is designed to measure magnetic vector and gradient signals of the same point. Invariants of magnetic gradient tensor measured by the array are used to determine whether there exists magnetic heading perturbation. Then the magnetic vector signals generated by the near-surface magnetic interference sources are calculated using the measured magnetic gradient signals based on the phase shift theorem of discrete cosine transform (DCT), and the background geomagnetic vector field is obtained by subtracting the inversed magnetic anomaly vector signals from the measured magnetic vector signals. Finally, the magnetic heading angle is obtained based on the compensated background geomagnetic vector field. Numerical examples and real experiments based our prototype array reveal reliability and the applicability of the proposed method.