3-D Imaging Method of Ship Target for InISAR Based on Second Selection of Time Window

Aiming at the problem that the reconstruction accuracy of the existing three-dimensional (3-D) imaging algorithm for interferometric inverse synthetic aperture radar (InISAR) is not high under the complex condition of ship motion characteristics, a 3-D imaging algorithm with high reconstruction accuracy based on second selection of time window is proposed. Firstly, the echo signal model of the ship target for the InISAR system with three antennas is established, and then the time window selection algorithm based on the instantaneous Doppler frequencies of multiple scatterers is used to realize the first selection of time windows for three channels respectively. Secondly, effective rotation vectors corresponding to each time window are estimated and a second selection of the time window of the InISAR system's echo signal is achieved based on the proximity level of effective rotation angles and 45°. Finally, the second selected time window is used to achieve InISAR 3-D imaging of the ship target. The proposed method can achieve higher accuracy in InISAR 3-D imaging of ship targets, and the simulation results validate the effectiveness and superiority of the proposed algorithm.