A Fast Bistatic Isar Imaging Approach for Rapidly Rotating Target

Effective bistatic Inverse Synthetic Aperture Radar (BISAR) imaging for rapidly rotating target raises issues due to spatial-variant range cell migration (RCM) and Doppler frequency modulation. In this paper, a fast BISAR imaging approach in the range-Doppler domain is proposed. First, the range-Doppler domain is exploited that a precise analytic format can be derived from the principle of stationary phase. Then, in terms of the complex RCM limited within the same range cell, an interpolation kernel based on the polar coordinate system is employed. To further reduce the computational complexity, interpolation-free mapping is involved through the principle of Chirp Scaling (PCS), which enhances computational efficiency by fast Fourier transforms and complex vector multiplication. Finally, simulation results demonstrate the effectiveness of the proposed BISAR imaging approach.