Three-dimensional super resolution ISAR imaging based on 2D unitary ESPRIT scattering centre extraction technique

摘要

Two-dimensional inverse synthetic aperture radar (2D ISAR) system can produce 2D electromagnetic images of a target, while failed to provide the 3D information. In this study, a novel method for 3D super resolution ISAR imaging is proposed via employing 2D U-estimation of signal parameters via rotational invariance technique (U-ESPRIT) and slice principle. First, the 3D scattered field data tensor is converted into a set of 2D matrix by stacking slices of the 3D data along one specific dimension. Then, 2D U-ESPRIT is applied to extract isolated scatterers from each slice. Combined with least-square method, complex scattering amplitudes are also estimated. Finally, 3D reconstructed scattering centres model with specific locations and complex scattering amplitudes is obtained, which can characterise the target to a great extent. The reverse process, reconstruction of the 3D ISAR image, can be readily done in real time by means of the extracted scattering centres. Experimental results are presented to demonstrate the effectiveness of the proposed algorithm.