Discrimination of Buried Objects in Impulse GPR Using Phase Retrieval Technique

This paper presents a modified signal processing technique of differentiating buried targets using impulse ground-penetrating radar. The technique is applicable to radargram; however, signal processing is carried out for each trace of the radargram separately. Every significant peak of each trace is compared with the peak of some calibration signal, for example, a signal that is reflected from the far interface of a thick rock slab. However, the calibration does not require the reference material be embedded in the medium, it can be in the air. The difference of phases between the object signal and the calibration signal is a function slowly varying with time that can be used for characterization of the buried object. The performance of the method is demonstrated in several examples using signals collected with the commercial impulse radar.