Fast beamforming algorithm for radar imaging through multilayered walls

A very fast beamforming algorithm is presented for the focused imaging of targets behind multilayered walls. The exploding reflection model is employed to simplify the imaging algorithm and then the layered medium Green's function is expanded in the spectral domain to facilitate the implementation of the algorithm with fast Fourier transform (FFT), which significantly accelerates the imaging speed. Numerical result is presented to show the effectiveness and efficiency of the proposed algorithm for radar imaging through multilayered walls.