Bistatic ISAR imaging under low SNR via fast complex approximate message passing

Compressive sensing (CS) has attracted much interest since it can be used to improve inverse synthetic aperture radar (ISAR) imaging. The complexity and robustness of imaging algorithm are two important aspects in CS-based ISAR imaging. In this paper, a fast complex approximate message passing (FCAMP) is presented to overcome strong noise and high-complexity for high resolution bistatic ISAR (B-ISAR) imaging. Approximate message passing (AMP) is extended to the complex field for realizing complex reconstruction in B-ISAR imaging. The calculation of matrix-vector multiplication is reduced from O(N²) to O(N logN) operations by fast Fourier transform. Simulated data are used to test the robustness and the speediness of the bistatic ISAR imaging framework with proposed FCAMP algorithm compared with other current methods. Experimental results show that the proposed approach is capable of effective suppression of noise and fast reconstruction of precise scattering centers.