The results of bistatic-radar and transillumination studies of the F-layer under the influence of powerful radio waves (Sura heating facility, Nizhny Novgorod) are presented. A highly directional receiving antenna (UTR-2, Kharkov) made it possible to detect and interpret a number of fine-structure characteristics of the Doppler spectrum of a signal scattered by a heated region. It is shown that, in addition to regular drift, there exists relative ordered motion of inhomogeneities in a perturbed region. The relative velocity is estimated. Deformation of the spectrum of a scattered signal in the states of development and relaxation is established and studied, and possible mechanisms of this phenomenon are discussed. Quasi-periodic variations of the amplitude and frequency of a scattered signal with periods of 30 sec to 5 min are detected. A comparison is made with the results of simultaneous radio transillumination of a heated region by signals from the point source Cassiopeia.