Building layout imaging with spatial filtering based on image optimization

The quality of through-wall-radar building layout image is affected seriously by the grating lobes when the element spacing of array is bigger than half a wavelength. Moreover, the image defocusing caused by the unknown wall penetration makes the problem worse. Based on the opposite characteristics of the low-frequency phase change of wall image area and the high-frequency phase change of grating lobes area, in this paper, a low-pass spatial filter is designed properly to reduce the grating lobes. The simulation results demonstrate the frequency characteristic of phase change and the through-wall-radar experiment results validate the feasibility of the low-pass filter in suppressing grating lobes.