Abstract:
This study presents the development of a discrete algorithm for interpreting groundpenetrating radar (GPR) data in vertically inhomogeneous media for the diagnostics of
road structures. Experimental data were obtained using an OKO-2 GPR system, followed
by primary radargram processing using the CartScan software. This included noise and
interference filtering, as well as the initial estimation of the dielectric permittivity of detected layers. The resulting dataset was used to validate numerical algorithms for solving
the forward and inverse problems of geolectrics. The proposed approach is based on
minimizing a quadratic misfit functional between the calculated and observed values of
the horizontal component of the electromagnetic field. The gradient of the functional
required for optimization is obtained via the numerical solution of an adjoint problem.
A discrete version of this problem was developed, which satisfies the properties of conservativeness and uniformity according to finite difference theory. The inverse problem
reconstruction of dielectric permittivity is considered a non-destructive method for radargram interpretation. Assuming a piecewise-continuous medium structure eliminates the
need for computing gradients at material interfaces. The proposed methodology enhances
the accuracy and reliability of pavement condition assessment and holds practical value for
road infrastructure monitoring.
