Comparison of the Imaging Resolutions of Time Reversal and Back-Projection Algorithms in EM Inverse Scattering

The imaging resolutions derived by the time reversal (TR) and back-projection (BP) algorithms, which are widely used in electromagnetic inverse scattering problems, have been investigated in this letter. Under the Born approximation, the point spread functions (PSFs) for TR and BP are first derived and then used to compare their imaging resolutions. The PSFs are examined by numerical experiments, which show that the TR and BP algorithms have the same imaging resolutions whether in the free space or the layered media cases.