基于TC-Relax的舰船目标ISAR成像

ISAR Imaging of the Ship Target Based on TC- Relax

由于舰船目标运动复杂,导致其回波信号平动补偿后方位相位存在三次项,若采用传统方法对其进行ISAR成像,图像质量将下降。针对这一问题,提出基于TC-Relax的成像算法对舰船目标进行ISAR成像。通过分析时间-调频率分布并结合解线调频Relax搜索方法对调频率变化率,调频率,中心频率,初相以及幅值这几个参数进行估计,从而实现舰船目标的ISAR成像。该方法不仅解决了成像质量下降的问题,也提高了参数估计的精度。通过舰船目标的仿真结果证明了该方法的有效性。

Due to the complex motion of the ship target,the azimuth of the echo signal has cubic phase after the translation compensation. If the traditional method is used for the target imaging,the imaging quality will decline. In order to solve this problem,a method based on TC- Relax is proposed in this paper. By using DechirpRelax searching and analyzing the time- frequency distribution, the parameters of the scatters such as the change of chirp rate,the chirp rate,the center frequency,initial phase and magnitude are estimated. Finally an ISAR image of the ship target is obtained. This method not only solves the problem of the imaging quality, but also improves the accuracy of parameter estimation. The simulation results show that the method is effective.