超宽带穿墙SAR成像中的多径干扰抑制

Multipath Interference Suppression for Through-the-wall SAR Imaging

超宽带穿墙合成孔径雷达(SAR)进行成像时,目标之间的多径传播会在图像上产生虚假目标,这将严重影响目标的检测性能和系统的灵敏度。建立了超宽带穿墙SAR的多径散射模型,通过分析得到多径产生的虚假目标的重要特征:方向依赖性,据此提出了一种基于隐马尔可夫模型(HMM)的多径干扰抑制方法。仿真结果表明,该方法能够使真假目标的峰值比提高11 dB左右。

When through-the-wall ultra-wideband（UWB） synthetic aperture radar（SAR） is applied to imaging,the interference of multipath spreading among targets introduces ghosts into the SAR image.It can deteriorate the detection and recognition capability of the radar system.A multipath scattering model is first developed for through-the-wall UWB SAR.By analyzing the model, an important feature of multipath ghosts is found in through-the-wall UWB SAR images,that is,aspect dependence.Based on the ghost′s aspect dependence,a hidden Markov model（HMM） based method is developed for the suppression of ghosts.Simulations show that the proposed method can improve the peak value ratio of real targets and ghosts by about 11 dB.