Use of sparsity in nonlinear electromagnetic imaging: wavelet-based contrast source method

A contrast source inversion (CSI) algorithm is developed in the wavelet domain in order to tackle nonlinear electro- magnetic inverse scattering with the benefit of sparsity. The soft-thresholding technique is applied here to sparsify the reconstruction. Numerical results show the potential of the proposed approach to improve the quality of reconstruction compared to the original CSI method.