Fast time domain algorithm for missile-borne bistatic forward-looking SAR based on ground elliptical polar coordinate

Missile-borne bistatic forward-looking synthetic aperture radar (BFSAR) plays a significant role in precise terminal guidance and attacking of the missile. However, its special configuration and operational mode would induce the large spatial variances and serious range-azimuth coupling of echo data, which increases the difficulty of the precise image formation. In this paper, a fast time domain algorithm based on the ground elliptical polar coordinate is proposed to focus the missile-borne BFSAR data precisely. It represents the subimages on the ground elliptical polar grids to reduce the computational burden. The imaging geometry and signal model of the missile-borne BFSAR are firstly established. Then, the implementation of processing the missile-borne BFSAR data using the fast time domain algorithm is presented. Finally, simulation experiment is carried out to prove the correctness of the theoretical analysis and the validity of the proposed method.