The paper describes results of experimental investigations into the radar sounding of inhomogeneous media and objects with the use of both multifrequency scanning in a superwide band (from 0.5 to 17 GHz) and nanosecond and subnanosecond pulses. It is shown that measurements supplemented with angular and spatial scanning with the synthetic-aperture radar (SAR) technologies make it possible to realize 3-D tomography of weakly contrast inhomogeneities with a spatial resolution of 1 cm. Data handling is based on applying physical models of interaction of electromagnetic radiation with the matter, which isolate dominating interaction mechanisms. This enables one to essentially simplify solution of the inverse problems and to use fast algorithms in solving. The radiation focusing is carried out with the use of mirrors, lenses, as well as the methods of 3-D coordinated Wiener filtering with regularization. Examples are given demonstrating the feasibility of the method for contactless tomography of the forest structure, detection and visualization of anti-infantry land mines hidden under a rough surface of sand. The description is given of the experimental installations developed. We have shown that the use of ultrabroadband radiation (UBBR) enables one to increase significantly the measurement accuracy while performing data processing on a real time scale.