A. Yu. Grinev - Dr.Sc. (Eng.), Professor
V. S. Temchenko - Dr.Sc. (Eng.), Professor
D. V. Bagno - Ph.D. (Eng.), Associate Professor
A. E. Zaikin - Ph.D. (Eng.), Senior Research Scientist
E. V. Ilyin - Ph.D. (Eng.), Senior Research Scientist

Results of investigations, elaboration and testing of ground penetrating radar (GPR) are presented. The GPR uses ultra wide-band short-pulse sounding signal and is applicable to diagnostics of road coatings and underground inhomogenities search down to 1,2 m depth. Its principle of operation and design, parameters and calibration procedures are discussed. Results of road coating's electro-physical and geometrical parameters restoration, subsurface objects' 3D imaging and geometry finding are presented. Multi-channel GPR software comprises developed methods and algorithms. The software's structure and its modules are discussed. The provides graphic user interface, GPR control, scattered electromagnetic field registration, primary and secondary processing, forming of radio images of subsurface objects, diagnostics of plane layered media and objects. A module of 2D and 3D radio images forming is presented in details, which is based on the , methods of range migration and reverse projections. Experimental results of four-layer medium parameters' reconstruction are discussed. Different electromagnetic models of T-horn antenna are used. Cross-sections of target function (the functional) are shown, which is multi-parameter, non-convex and multi-extremal. Algorithms of global optimization are used to find true minimum of that functional. Cross-section's structure has multiple local minima, so gradient methods are not effective. Results of experimental restoration of road coating's and underground objects' electro-physical and geometrical parameters restoration are presented, 3D images are shown.