A high-precision calculation method for the magnetization field of airframe

To achieve high-precision measurement of geomagnetic sensors in geomagnetic navigation and eliminate the interference magnetic field generated by ferromagnetic carriers at measurement points, a carrier magnetization field calculation model is proposed. The improved adaptive cross approximation algorithm (IMACA) is used to decompose and inverse the coupling coefficient matrix of discrete elements, ensuring the accuracy of magnetization field calculation while reducing memory requirements and calculation time during the calculation process, and verified through numerical simulation of the spherical shell. A equivalent magnetization inversion model based on the Nelder-Mead algorithm has been proposed, which can obtain a more accurate distribution of the equivalent magnetization of the carrier model. The results of ANSYS simulation of the carrier model and experimental results of the carrier scaled model show that the errors of the three-axis components and total amount of magnetic induction intensity at the measurement points are 3.67%, 0.98%, 4.23%, and 1.03%, respectively. This verifies that the carrier magnetization field calculation model can achieve high-precision calculation of the carrier magnetization field. This solution model can not only be applied to the calculation of magnetization fields in ships and submarines, enhancing their protective capabilities, but also to the calculation of magnetization fields in torpedoes and landmines, achieving long-distance detection of torpedoes and landmines.