Deep Penetration Radar: Hydrogeology and Paleorelief of Underlying Medium

We discuss geophysical applications of enhanced-power ground penetrating radar. Its technical characteristics assure penetration depth and resolution sufficient for probing weak subsurface boundaries, such as buried riverbeds or interfaces between natural and artificial grounds. Examples of deep GPR scans demonstrate weak protracted echo signals originated at smooth permittivity gradients of the subsurface medium. Their quantitative interpretation can be done with the help of time-domain version of coupled WKB approximation.