Inversion of Magnetic Dipole Parameters Using a Scalar Field Gradiometer

Magnetic anomaly detection (MAD) from military patrol aircraft is a trusted technique for detecting a submarine. The final goal of MAD is to obtain reliable target localization and identification. This task could be accomplished if the MAD system comprises two scalar magnetometers that are combined to form a gradiometer, and the target is modeled as a dipole. The present work proposes a novel algorithm to solve the dipole localization problem. It is shown that a set of linearly independent functions can accurately describe the scalar magnetic field gradient for a wide range of separation distances between sensors. Decomposition of the signal in the space of these functions allowed the estimation of the target position and its magnetic moment. The solution is unique although affected by errors from the estimation of the gradient when a finite baseline separates the sensors. Statistical processing of computer simulation results shows good algorithm convergence and acceptable relative errors of target parameters estimation.