V. N. Tsymbal, S. E. Jatsevich, D. M. Bytchkov, A. S. Gavrilenko, V. B. Efimov, A. S. Kurekin, A. Ya. Matveev

In the article features of studying underground objects, geological structures and mineral deposits by means of multifrequency radar remote sensing from aviation carriers are considered. As now there is no the unequivocal physical model allowing strictly to describe processes of dispersion of radio-waves by various objects, located under a layer of soil. In the article the simplified model which allows to interpret confidently the results received with use of multifrequency radar remote sensing is analyzed. The briefly considered mechanism allows to estimate possibility of surveying of the objects located in a layer of soil and forming "strong" scatterings, against dispersion by a surface and to estimate features of their radar supervision on various frequencies and signal polarizations. It becomes important at detection of geological structures or objects under a soil layer as in some cases, for example, dry sand they can be found out on considerable depths. Results of the theoretical analysis and modelling of processes underground the radar sensing, resulted in article, convincingly testify to basic possibility of detection by radar means located under a soil surface of artificial constructions, geological and hydrological structures. Thus, the most perspective is use of multifrequency and multipolarizing radar sensing simultaneously in meter and more short-wave (for example centimeter and decimeter) bands of radio-waves. The best results are reached in arid and other droughty areas thanks to deeper penetration into soil of radio-waves. Numerous experiments confirm these conclusions. In the article results of special experiments on detection of underground objects by means of simultaneous sensing in millimetric, centimetric, decimeter, and meter ranges of lengths of waves are resulted by multifrequency radar complex "MARS". The structure of the complex established onboard the plane - laboratories IL-18D contains sidelooking radars of millimeter and centimeter bands, and SAR of decimeter and meter bands. One of the realized experiments on detection underground objects passed in desertificated areas in the central Kara Kum nearby to the Tedzhensky oasis in Turkmenia. The surface representing sandy barkhans, represented favorable conditions for detection of objects owing to strong penetration of radio-waves under a surface. Also experiments were realised in soil conditions, characteristic for an average strip of Ukraine where various kind "chernozems" prevail, and for detection and identification of displays of geological structures (first of all fracture structures) in the conditions of a permafrost (the Arkhangelsk region, Russia). The resulted experimental radio images the laboratories IL-18D received onboard the plane in a wide band of frequencies, and also their processing have shown possibility of radar sensing underground objects with high contrast on horizontal polarization in decimeter and meter bands of radio-waves.