Improved Ellipsoid Fitting Method Based on Tensor Mix Source Separation for Correcting the Three-Component Magnetometer

The ellipsoid fitting method is often used to correct the error of the three-component magnetometer, but when nonalignment error and/or soft magnetic interference are large, this method cannot correct the error accurately, because there exists a rotation matrix between the corrected error matrix and the real error matrix. In this article, a tensor correction method of the three-component magnetometer with improved ellipsoid fitting is proposed. First, zero bias and/or equivalent hard magnetic interference and ellipsoidal error matrix are obtained by ellipsoid fitting method. Second, the rotation matrix is obtained by mix source separation based on tensor analysis after ellipsoid fitting. Finally, the ellipsoidal error matrix is multiplied by the inverse of the rotation matrix to get the real error matrix. Both the simulation results and the actual experiment result show the correctness and engineering practicability of the proposed method.