ICSI: an improved contrast source inversion method for electromagnetic inverse scattering problems.

An improved contrast source inversion method (ICSI) is proposed to solve the problem of electromagnetic inverse scattering. Specifically, we first resort Fourier bases to represent contrast source, so that we can solve contrast source in the frequency domain, which can accelerate the solution of contrast source. Then, a spatial-frequency domain constraint is designed to ensure that the spanned-domain calculation is synchronous optimal. Afterwards, a multi-round optimization combined with SVD (the singular value decomposition) is developed to alleviate the reliance on initial guesses. Finally, we utilize a frequency-domain filter to eliminate redundant inversion information and narrow the search scope of the solution. Extensive experiments on the synthetic and real data show that ICSI holds a faster computing speed, a better inversion ability of relative permittivities, and a stronger anti-noise ability.