A close approximate method of slant range for through-wall-radar imaging

Electromagnetic waves penetrating through walls will experience refraction and velocity change which must be taken into account for accurate through-wall-radar imaging (TWRI). Calculation of actual slant range is critical for TWRI. However, the existing methods are complex and time-consuming; a close approximate method of slant range is presented in this paper which estimates the propagation distance as a summation of a straight distance between antenna and target and a constant range migration determined by wall parameters. The simulation results show that the proposed method achieved good approximate capability in different wall parameters. Based on this approximate method, Range-Doppler imaging algorithm is firstly introduced in TWRI. Imaging results are given to demonstrate that the proposed method can compensate refraction effect and focus target on the right position.