A Novel Probability Model for Suppressing Multipath Ghosts in GPR and TWI Imaging: A Numerical Study
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摘要: 该文提出了一种抑制探地和穿墙成像中多径虚假目标的新方法, 虚假目标主要来源于基于伯恩近似的线性成像算法, 该方法忽略了目标之间的多次散射。相对已有抑制多径虚假目标的方法, 该文的主要贡献有两个方面:(a)目标反射率第一次用概率函数模型表征, (b)成像过程中引入随机孔径(从整个孔径中随机选取获得)的概念, 因此, 最终雷达图像可以理解为由随机子孔径得到图像相乘获得的联合概率分布。最后, 通过一组数值算例验证了该方法在探地和穿墙成像中的有效性。Abstract: A novel concept for suppressing the problem of multipath ghosts in Ground Penetrating Radar (GPR) and Through-Wall Imaging (TWI) is presented. Ghosts (i.e., false targets) mainly arise from the use of the Born or single-scattering approximations that lead to linearized imaging algorithms; however, these approximations neglect the effect of multiple scattering (or multipath) between the electromagnetic wavefield and the object under investigation. In contrast to existing methods of suppressing multipath ghosts, the proposed method models for the first time the reflectivity of the probed objects as a probability function up to a normalized factor and introduces the concept of random subaperture by randomly picking up measurement locations from the entire aperture. Thus, the final radar image is a joint probability distribution that corresponds to radar images derived from multiple random subapertures. Finally, numerical experiments are used to demonstrate the performance of the proposed methodology in GPR and TWI imaging.
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