The Effect of Secondary Reflections on the Quality of Layers Thickness Assessment Using UWB GPR Signals

The paper presents the results of experimental studies on the effect of secondary reflections arising from the registration of ultra-wideband ground-penetrating radar signals when the antenna unit is located in close to the external boundary of the probed medium. In this case, when using the standard calibration procedure to obtain the parameters of the sensing signal and then measuring the signals reflected from the medium under study, it is necessary first of all to investigate the effect of such secondary reflections on the resulting data sets. When formulating and solving such problem, it is necessary to take into account the specific features of real antennas and the shape of the pulse signals radiated and received by them. The main goal of the experiments is to study the influence of the distance between the antennas and the surface of the examined medium and the subsequent optimization of the measurement technique for signals reflected from plane-layered media. An analysis of the obtained experimental results shows the possibility of further improving the quality of non-destructive testing of road pavements and other constructions using pulsed UWB georadars.