用于线阵三维SAR成像的二维快速ESPRIT算法

摘要

The linear array Synthetic Aperture Radar (SAR) system is a popular research tool, because it can realize three-dimensional imaging. However, owning to limitations of the aircraft platform and actual conditions, resolution improvement is difficult in cross-track and along-track directions. In this study, a two-dimensional fast Estimation of Signal Parameters by Rotational Invariance Technique (ESPRIT) algorithm for linear array SAR imaging is proposed to overcome these limitations. This approach combines the Gerschgorin disks method and the ESPRIT algorithm to estimate the positions of scatterers in cross and along-rack directions. Moreover, the reflectivity of scatterers is obtained by a modified pairing method based on “region growing”, replacing the least-squares method. The simulation results demonstrate the applicability of the algorithm with high resolution, quick calculation, and good real-time response.%线阵3维SAR系统可实现对地面场景的3维成像，是近年来研究的热点。但受载机平台和硬件条件的限制，其切航迹向和沿航迹向的分辨率难以提高。为了改善2维分辨率，该文提出了一种用于线阵3维SAR成像的2维快速ESPRIT算法，首先结合盖式圆方法和ESPRIT算法估计出点目标在切航迹向和沿航迹向位置，并通过该文改进的基于“区域生长”的2维位置配对方法替代最小二乘法快速求得目标散射系数，实现线阵2维SAR切航迹向和沿航迹向超分辨成像。该算法具有分辨精度高、运算速度快、实时性能好等优点。仿真实验证明了其有效性。