Byrkov I. A., Filippskikh E. E.

observation is described. The technique is based on the use of 3D digital country models and database of reflection characteristics of typical surfaces in the UHF range. The technique ensures evaluation of radar images in the form of matrices of intensity samplings for signals accepted by the radar. Initial data for evaluation of prognosis radar images are: the 3D digital country model; reflection characteristics of typical artificial and natural surfaces in the UHF range; technical characteristics of the observation equipment; current conditions of observation. The use of 3D digital country models ensures taking into account metrical and semantic properties of object surfaces. The reflection characteristics database provides evaluation of radar cross-section for various classes and types of surfaces with taking into account signal parameters and observation conditions, including small backing angles. The technique for computation of radar images consists of two stages: computation of the scene energy portrait; computation of the model radar image. Computation of the scene energy portrait is performed within geometric optics assumptions, by tracing a 3D country model with outgoing rays. This approach gives possibility to compute radar images obtained by radar stations with synthesized aperture, with scanning and front-lateral surveillance. To improve adequacy of computed radar images to experimental images, the authors developed a technique for defining parameters of radar sensors by experimental data. Moreover, using the results of analysis of an experimental data representative sampling obtained with using the synthetic aperture radar - Compact-100?, a model for forming radar vegetation portraits with using statistical and correlation properties was developed. In the article, the results of qualitative and quantitative estimate of correspondence between computed (prognosis) and experimental radar images are presented. The results obtained allow making the conclusion about high level of adequacy of radar images obtained by using the authors technique and possibility of its use for quick generation of prognosis radar images during the pre-flight preparation of UAV complexes and flying vehicle crews, as well as for processing results of country radar surveillance.