On the Instantaneous Phase of GPR Response for Concrete Relative Permittivity Estimation

The use of ground penetrating radar (GPR) in civil engineering is widely established in many possible applications including inspection of the concrete internal structure and its defect. To make a thorough analysis on the inspection, the accurate dielectric constant information is needed. Some material permittivity estimation methods are available but those methods mostly use the amplitude of GPR response as main information. This paper presents the analysis of the feasibility of instantaneous phase information of air-coupled GPR response as a new feature to measure the concrete permittivity. Through numerical simulations based on the finite-difference-time-domain method, this feature is promising to be employed in future possible applications. However, since the correlation changes depend on the GPR configuration and pulse waveform, the multi-parametric approach needs to be developed to make a general and reliable formulation of permittivity estimation technique.