A beamforming approach to stepped-frequency synthetic aperture through-the-wall radar imaging

A data-adaptive stepped-frequency synthetic aperture radar system based on quadratically constrained Capon beamforming is presented for through-the-wall wideband microwave imaging applications. Various effects of the presence of the wall, such as refraction, change in speed, and attenuation, are incorporated into the beamformer design. Proof of concept is provided using real data collected in a laboratory environment. The results show that the proposed Capon beamformer outperforms the non-adaptive through-wall delay-and-sum beamformer.