ISAR Imaging of Fluctuating Ship Target Based on a Novel Approach for Cubic Chirplet Decomposition with Local Polynomial Wigner Distribution

A new technique for the cubic Chirplet decomposition via local polynomial Wigner distribution (LPWD) is presented. Through introducing the parameter of curvature to the traditional Chirplet atoms, the cubic Chirplet atoms are more accurate to characterize the signals with high nonlinear instantaneous frequency (IF) trajectories. The phase coefficients of the cubic Chirplet atoms are evaluated by the LPWD algorithm with two-dimensional (2D) maximizations. This technique is precise, with high efficiency, and it is used in inverse synthetic aperture radar (ISAR) imaging of ship target with complicated motions, the ISAR images with good quality can be achieved. Experiments of emulational and real data validate the effectiveness of the new algorithm.