Electromagnetic tomography imaging of coaxial differential coils based on Linear Back Projection, Tikhonov and Landweber algorithms

In this paper, a challenge in detecting internal defects of high-voltage cables is addressed by proposing an electromagnetic tomography (EMT) technique based on coaxial differential coils. An 8 -coil sensor array is established using COMSOL finite element simulation software. By employing linear back projection (LBP), Tikhonov regularization, and Landweber iteration algorithms, the performance advantages of differential coils in suppressing noise and enhancing image quality are systematically investigated and compared with traditional single-coil structures. The results show that, for the same defect location, the reconstructed images from the differential coils exhibit an improved signal-to-noise ratio and superior visualization.