Enhancement of static human-to-background contrast in through-the-wall polarimetric radar ISAR measurements

The human-to-background power contrast in fully-polarimetric Inverse Synthetic Aperture Radar 6-11 GHz images has been enhanced by computationally varying the transmit and receive antenna polarizations. The static scene contained a sitting human in a sparsely furnished room with wooden walls. Two contrast enhancement procedures, taken from the literature, were tested: one iterative scheme, based on the Kennaugh matrix, and one scheme, based on the covariance matrix, which uses the Lagrange method for constrained optimization. The highest contrast increase was generally obtained with the iterative procedure, typically of the order of a few dB relative to the horizontal/vertical transmit/receive combinations.