Magnetic tag recognition via high-order projection of far-field measurements

This study presents a novel method for recognizing magnetic tags based on far-field measurements using high-order projection techniques. Magnetic tags consisted of a 2× 2 array of neodymium permanent magnets, each treated as a dipole with a distinct magnetization state. The experimental measurements of the magnetic flux (Bz) were conducted using a Hall axial probe and xy translation stage. The proposed recognition algorithm employs two methods: Taylor series expansion and spectral continuation with regularization. The results demonstrate the ability of the algorithm to identify distinct magnetic tag signatures, particularly for intricate configurations. The spectral method with regularization is suitable for large continuation distances and can be adapted to very large distances using multistep scheduling.