Detecting and classifying of physical and geometrical characteristics of the subsurface through the use of computing diagnostics method for ground-penetrating radar

The method of computational diagnostics has been recently developed to determine the depth of layers and their electrophysical parameters related to structural diagnostics (monitoring of road pavements, runways, etc.). The method of computational diagnostics is based on minimizing a certain smoothing functional, which includes a functional of discrepancy between the resulting measurements of scattered electromagnetic field and the results of a direct model problem, and also a stabilizing functional accounting for a priori data on the electrophysical and geometrical parameters of a sounded object (medium). The solution minimizing this functional is found both by one of the iterative techniques (simple iteration, steepest descent, conjugate gradients, etc.) and direct techniques. The problem discussed is related to the complexity of searching for a global minimum of the finite dimensional spaces of the layer parameters, when this complexity is brought about by the multiple-extremality of the functional. The examples are presented of the actually restored electrophysical and geometrical medium parameters by using a video pulse ultra-wideband ground penetrating radar.