Accurate analysis of GPR first-arrival signals for the evaluation of soil permittivity parameters

This work is aimed at investigating the relationships between amplitude attributes of the `first-arrival direct wave´ (also called `early-time signal´, ETS, in brief), which propagates at the interface in bistatic ground penetrating radar (GPR) configurations, and the relevant shallow-soil permittivity parameters (dielectric constant and conductivity). Our analysis is developed by considering the characterization of the involved problem both from measurements, in a controlled experimental setup, and from simulations, with an efficient numerical implementation based on a CAD tool. Suitable ETS attributes able to give predictable correlation with the ground permittivity values are evaluated as a function of various system parameters. Accurate results are provided and discussed, allowing us to emphasize the distinctive features of this technique. Potential and critical aspects for effective geophysical applications of ETS can consequently be addressed.