State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System, National University of Defense Technology, Changsha 410073, China.
Naval Research Academy, PLA (NVRA), Beijing 100000, China.
Sensors (Basel). 2018 Sep 13;18(9):3082. doi: 10.3390/s18093082.
Due to the sparsity of the space distribution of point scatterers and radar echo data, the theory of Compressed Sensing (CS) has been successfully applied in Inverse Synthetic Aperture Radar (ISAR) imaging, which can recover an unknown sparse signal from a limited number of measurements by solving a sparsity-constrained optimization problem. In this paper, since the V style modulation(V-FM) signal can mitigate the ambiguity apparent in range and velocity, the dual-channel, two-dimension, compressed-sensing (2D-CS) algorithm is proposed for Bistatic ISAR (Bi-ISAR) imaging, which directly deals with the 2D signal model for image reconstruction based on solving a nonconvex optimization problem. The coupled 2D super-resolution model of the target's echoes is firstly established; then, the 2D-SL0 algorithm is applied in each channel with different dictionaries, and the final image is obtained by synthesizing the two channels. Experiments are used to test the robustness of the Bi-ISAR imaging framework with the two-dimensional CS method. The results show that the framework is capable accurately reconstructing the Bi-ISAR image within the conditions of low SNR and low measured data.
由于点散射体和雷达回波数据的空间分布稀疏,压缩感知(CS)理论已成功应用于逆合成孔径雷达(ISAR)成像中,通过求解稀疏约束优化问题,可以从有限数量的测量中恢复未知稀疏信号。在本文中,由于 V 型调制(V-FM)信号可以减轻距离和速度上的模糊性,因此针对双基地逆合成孔径雷达(Bi-ISAR)成像提出了双通道、二维、压缩感知(2D-CS)算法,该算法直接基于求解非凸优化问题处理二维信号模型进行图像重建。首先建立目标回波的二维超分辨模型;然后,在每个通道中应用二维 SL0 算法,并通过合成两个通道得到最终的图像。实验用于测试二维 CS 方法的 Bi-ISAR 成像框架的鲁棒性。结果表明,该框架能够在低 SNR 和低测量数据条件下准确重建 Bi-ISAR 图像。