Real-time localization method for cooperative magnetic target based on magnetic gradient tensor

Abstract

Magnetic anomaly detection (MAD) has been increasingly prevalent because of advantages of the magnetic field such as strong penetrability and low power cost. An innovative real-time localization method based on calculation of the eigenvalues of the magnetic gradient tensor is proposed in this paper. The angle between displacement vector and magnetic moment vector can be expressed in terms of eigenvalues of the magnetic gradient tensor. In specific applications like localization of cooperative magnetic target of which the magnitude of the magnetic moment is known in advance, the distance between the target and the magnetic gradiometer can be derived using the magnetic tensor contraction. Numerical simulation result shows the robustness of the distance determination algorithm. What is more, the positioning principle in satellite navigation is introduced and applied to finally realize real-time localization. Simulation compares the method with another analytic localization method, and the result proves the high-precision of the method even under noisy environment.