Ground Penetrating Radar Signal Analysis Using Complex Continuous Wavelet Transform

The lack of efficient management may potentially lead to dangerous situations in which the underground pipes, rebar, etc., are destroyed during engineering excavation. It is important to know the positions of these objects to prevent the risk of destroying structures and incurring additional cost. By applying different methods to potential objects, we can quickly detect approximate locations of underground objects by using ground penetrating radar in an economical way. The images can be displayed in real time. After on-site interpreting by professionals with relevant experience, the stratigraphic picture of the area can be roughly depicted. Furthermore, other post-processing technologies may enhance the signal characteristics. In this study the test data provided by previous research are used as raw signals in applying the complex continuous wavelet transform. Both time domain and frequency domain results were analyzed by translating at different scales. The changes in dielectric constant can be highlight and then we can infer the approximate locations of the objects in the ground. The complex continuous wavelet transform can display not only the amplitude but also the phase angle changing with time and frequency. The amplitude can be enhanced in the shallow signals, however, the deep signals completely lose the oscillation characteristics. Unlike the amplitude, the phase angle doesn't attenuate rapidly. These two completely different features can be compared with the radar image at the same time, improving interpretation efficiency. © 2021, Chinese Institute of Civil and Hydraulic Engineering. All right reserved.