A back-projection algorithm to stepped-frequency synthetic aperture through-the-wall radar imaging

Back projection imaging algorithm is widely used in through-the-wall and GPR imaging because of the high image quality and being compensated easily. In this paper, the author will introduce the back projection algorithm to the stepped frequency through-the-wall radar and put forward the time-minimization method to eliminate the wall's effects, such as refraction, changing in speed and attenuation. Proof of concept is provided using real data collected in a laboratory environment. The results show that the BP algorithm can outputs a high quality image and the time-minimization method can eliminate the wall's effect very well.