Characterization and mitigation of air-coupled GPR antenna vibration during traffic-speed estimation of asphalt pavement dielectric constant

Accurate prediction of the dielectric constant is essential for asphalt pavement layer thickness and density estimations using air-coupled ground-penetrating radar (GPR) antennas. However, antenna vibrations during continuous dielectric constant profiling introduce noise, causing inaccurate predictions. The existing method only smooths the profile without analyzing the air-coupled antenna's transmitter and receiver vibration mechanisms. Precise transmitter and receiver movements are challenging to quantify for commercialized antenna models. This study investigates different dimensions of antenna movements during continuous dielectric constant profiling using GPR to assess the effect of vibrations on prediction accuracy. The simulation model was built to reconstruct the antenna vibrations at different dimensions. A signal filtering method was proposed to attenuate the vibration effect in the dielectric constant profile based on the frequency domain features. Prediction errors drop from 4.65 % to 2.83 % at various speeds using the proposed method. The outcome of this study could allow robust and automatic attenuation of antenna vibration during traffic-speed GPR surveys.