Differential Inverse Scattering Imaging of PEC Scatterers within Inhomogeneous Media

In this work, the electromagnetic inverse scattering problems of perfect electric conductor scatterers (PECs) within inhomogeneous media are investigated. A general differential inversion framework is proposed, which effectively incorporates the influence of the background media. The contours of PECs can be reconstructed by solving the intensity of differential contrast source (DCS). Both nonlinear optimization methods and linear approaches can be integrated into this framework. In particular, considering the computational burden, a novel differential linear inversion method is proposed and emphasized. Furthermore, to mitigate the ill-posedness, a joint sparse regularization scheme is employed. To accommodate different signal-to-noise ratios (SNRs), a sensitivity analysis of the regularization parameter is performed to provide guidance for its practical selection. Finally, the imaging accuracy, robustness, and computational efficiency of the proposed method are validated through both synthetic and experimental data. Comparative analyses with state-of-the-art inversion techniques further confirm its superior reconstruction performance.