Study of the secondary characteristics of the bistatic scattering of a combined object in a covert radar surveillance system.

Abstract

The emergence of new means of attack, reconnaissance and methods of sabotage imposes special requirements on the technical means of protecting important state facilities (ISF). Modern trends in the construction of ISF physical protection systems are the integration of engineering barriers, perimeter signaling and detection tools. Detection tools should provide covert receipt of information about the approach of the intruder in «distant» intrigues. To do this, it is possible to use technical means built on the principle of semi-active bistatic radar with an external illumination source. However, in order to identify intruders in the ISF protection zone, it is necessary to have a priori information about the radar visibility of the combined location objects. The combined object is typically a complex object having both metallic and dielectric elements. To this end, a technique has been developed for estimating the radar cross-section (RCS) of combined objects in the field of external illumination. The electromagnetic field (EMF) scattered by a combined object in the meter and decimeter wavelength ranges is calculated as a coherent sum of fields, taking into account their phase, scattered by its metal and dielectric elements. This made it possible to take into account the electromagnetic interaction of the elements of the combined object. The method of integral equations (IE) was used to find the current density and magnetic field strength. The scatter diagrams of the person-intruder, the person-intruder in personal armor protection (PAP) under different conditions of irradiation and reception and illumination frequencies are obtained and analyzed. This made it possible to evaluate the effect of metallic elements on the scatter diagram of the combined object. The obtained a priori information is of significant practical importance at the stage of optimizing signal processing algorithms and designing new means of covert detection.