散射中心的时频像特征研究

Research on Signatures of Scattering Centers Shown in Time-frequency Representation

散射中心是高频区电磁散射的重要特征,其属性特征,如散射幅度、位置,对方位的依赖性对于雷达成像及目标识别具有重要意义。与其它雷达图像相比,时频图像能更完整地反映出散射中心的属性特征,但目前关于不同散射中心的时频像特征研究还不完整。该文首先基于散射中心模型,从理论上分析了各个散射中心时频像的特征,然后通过全波法电磁计算得到了典型结构目标的散射数据,从数值上验证了对时频图像特征的理论分析,最后总结了不同散射中心的时频像特征,此结论有助于从时频像中直观地判断目标的散射中心类型和其对应的物理结构特点,可为基于时频像的雷达目标特征提取与识别提供一定的理论参考。

Scattering centers are important features of electromagnetic scattering at high frequencies. The aspect dependency of the amplitude and location of a scattering center has a significant influence on radar imaging and target recognition. Compared with other radar images, the Time-Frequency Representation（TFR） of radar returns more clearly presents features of scattering centers. In this paper, the signatures of TFR of different types of scattering centers are investigated theoretically and numerically. In numerical experiments, the scattering responses of several typical targets are computed by the full-wave numerical method. The conclusion of this paper on signatures of TFR of scattering centers can provide a theoretical reference for the feature extraction and target recognition from TFRs.