SAR Frequency-Shift Jamming Suppression Method by Shaping the Cross-Ambiguity Function

Frequency-shift jamming can generate line, strip, and area suppression images, which cover the region of interest, and thus, degrade the synthetic aperture radar (SAR) detection performance. In this article, a frequency-shift jamming suppression method is proposed by shaping the cross-ambiguity function. The integrated sidelobe level and peak value penalty function are formulated to obtain good pulse compression performance. The local ambiguity function level is also formulated to achieve jamming suppression performance. The SAR antijamming cross-ambiguity function shaping problem is then established under the practical constraints. By applying the block successive upper bound minimization and fast implementation based on fast Fourier transform, a fast and efficient joint design algorithm is derived, which has lower computation complexity than the cyclic algorithm on the basis of matrix inversion. Simulation results demonstrate the effectiveness and superiority of the cross-ambiguity function shaping method by jointly designing the waveform and mismatched filter, which obtains a lower local ambiguity function level and better pulse compression performance than the ambiguity function shaping method via waveform design. Moreover, the designed waveform and mismatched filter achieves best antijamming and SAR imaging performance compared with the existing waveform.