GPR Imaging With RM Algorithm in Layered Mediums

In ground-penetrating radar (GPR) imaging, the classic range migration (RM) algorithm can work well only when the imaging scene can be modeled as a single homogeneous medium. However, in most GPR field applications, the GPR system and objects operate in different mediums. The space between the antennas and the ground cannot be ignored electromagnetically. In this kind of circumstance, the imaging result of the classic RM algorithm will be blurred or possibly not focused at all, and the object´s physical location cannot be interpreted from the imaging result. A layered RM imaging algorithm is proposed in this letter. With the exploding source model, the received field is first back propagated to the ground surface, and then, the classic RM method is carried out to give the final imaging result. Experimental results show that the proposed algorithm can prevent the defocusing of the object and obtain the object´s true position. The computational time of the layered RM algorithm does not increase remarkably compared with that of the classic RM algorithm.