Ways to increase the efficiency of detection of unmanned aerial vehicles by thermal imaging devices

The possibilities to increase the efficiency of detection of air objects due to the optimized choice of a functional area of an infrared range of electromagnetic waves are mathematically estimated. It is shown that there is a need to use receivers with maximum visibility in longer wavelengths, as well as the need to work in the “transparency windows” of the atmosphere. With low visibility, long-wavelength infrared thermal imaging devices are advantageous at long distances from objects. Devices with more shortwave sensitivity can be effective over short distances. Radar detection methods in many cases are not able to detect small objects with a low reflection coefficient, which is one of the reasons for the small effective scattering area. Known methods of observation using night vision devices and thermal imaging devices, having their advantages, are also ineffective in certain conditions. An attempt is made to combine the advantages of detecting aerial objects by the multi-position radar method with the advantages of thermal imaging devices. A method of illuminating air objects with infrared searchlights is proposed, which implies the presence of many geometrically spaced sources of infrared radiation with a working spectrum combined with areas of “windows of transparency” of the atmosphere and the maximum sensitivity of the thermal imager. In such conditions, the receiver registers the total signal of thermal radiation of the object and the reflected rays of searchlights. Remote control of the spotlight emission, on which the effective scattering area depends linearly, makes it possible to bring it to the level guaranteed with a high probability of detecting a small flying object.