Through-wall propagation effects on Doppler-enhanced frontal radar images of humans

High-resolution frontal radar images of humans can be generated in free space conditions with a Doppler radar with a large radar aperture. Compressed sensing based two dimensional beamforming enables imaging of humans with sub-Nyquist number of elements in the radar aperture. In this work, we apply this imaging technique to humans in through-wall scenarios in indoor environments. Walls are complex propagation environments that introduce refraction, attenuation, ringing and multipath to the radar signal. In this work, we quantitatively analyze the impact of inhomogeneous walls on the direction-of-arrival estimation with array processing. Next, we examine the impact of wall clutter on compressed sensing based radar imaging. The radar data scattered by humans moving behind walls is simulated by hybridizing wall propagation models, derived through computational electromagnetic techniques, and electromagnetic primitive based models of moving humans.