An innovative method for measuring pavement dielectric constant using the extended CMP method with two air-coupled GPR systems

Ground penetrating radar (GPR) is a common non-destructive tool for pavement layer thickness measurement. The accuracy of such measurement is directly affected by the accurate prediction of the dielectric constant of pavement material using GPR. In this study, an innovative extended common mid-point (XCMP) method using two air-coupled GPR systems was developed to improve the accuracy of the traditional method for pavement material dielectric constant estimation. The equations and algorithm for calculating the dielectric constant of pavement material were developed, and then the accuracy of this new method was validated successfully by the data collected from a custom-designed test site.