Three-Dimensional Interferometric ISAR Imaging for the Ship Target Under the Bi-Static Configuration

In this paper, a novel three-dimensional (3-D) Interferometric inverse synthetic aperture radar (InISAR) imaging method, which especially works on the ship target, is presented. Considering the characteristics of the ship target and the 3-D InISAR system, the bistatic configuration is designed to avoid the imaging failure in special situations caused by the low velocity of the ship target. The specificity of the 3-D InISAR imaging technique makes the adoption of the optimal imaging time selection method based on the estimation of the Doppler center, which can help to select the imaging time when the cross-range resolution reaches maximum, effective and simple enough for the 3-D reconstruction of the ship target. Besides, the translational and angular motion compensations in such situations are explained clearly. Due to the shortness of the selected echoes caused by motion complexity of the ship target, the sparse Bayes learning method, which has a lot of advantages compared with other similar methods, is adopted to realize the super-resolution imaging for the purpose of separating the superposed scatterers and its superiority in reducing the computation load of the 3-D InISAR imaging system is demonstrated explicitly. Finally, the distortion of the reconstructed coordinate for the ship target caused by the bistatic configuration is corrected by the simplified coordinate transformation and the relationship between the coordinates of the ship target and the reconstructed 3-D model is explained in detail. Some experimental results are provided to substantiate the effectiveness of the 3-D InISAR imaging method for the ship target in this paper.