Target detection based on automatic threshold edge detection and template matching algorithm in GPR

When using ground-penetrating radar (GPR) detects targets in complex underground scene, due to the nonuniformity of underground medium, the disturbance of echo signal at the aspects of propagation path and propagation attenuation leads to the phenomenon of such as dislocation, missing, distortion characteristic of scattering curve in GPR record profile. Traditional methods of target localization based on hyperbolic vertex detection is no longer valid. In this paper, a method based on automatic threshold edge detection and template matching was proposed to reduce the influence of hyperbolic distortion and noise and improved the accuracy of vertex detection. Firstly, one-dimensional energy curves along the lateral line are recorded by GPR to determine preset number of targets. A preset range of target number was determined by recording a one-dimensional energy curve along a survey line by the GPR record profile. Secondly, the edge of GPR record profile was detected based on automatic matching threshold to obtain estimated vertex coordinates. Based on the estimated vertex coordinates, templates were established and template matching process was carried out to obtain matching target vertex; Finally, target vertices were filtered by clustering analysis and false vertices were removed, detection results of target vertex in GPR profile were obtained. Simulation and onsite GPR profile processing results show that the proposed method can effectively suppress the effects of hyperbolic deformation and noise with higher detection accuracy.