ENERGY CALCULATION OF SMALL-SIZED UAVs AUTOMATIC OPTOELECTRONIC OBSERVATION SYSTEMS

Great popularity of small unmanned aerial vehicles (UAVs) in remote observation tasks requires further improvement of not only the carrier, but also the on-board equipment. Standard means of surveillance for UAVs are television cameras. Thermal imaging cameras are used in more expensive technical solutions. The efficiency of the functioning of these devices primarily depends on spatial and energy resolution of their input units, which containe optical system and detector. Small-sized UAVs operate at short distances. The peculiarity of useful signal formation by optical-electronic surveillance systems (OESS) of such UAVs is the need to primarily ensure sufficient energy sensitivity. 
The article develops a method for determining the energy resolution of short-range automatic UESs with two information channels - television and thermal imaging. It is justified that for simplified calculations it is advisable to use the functions of the noise-equivalent luminance difference and the noise-equivalent temperature difference of the corresponding channel as quality indicators. Examples of energy resolution calculations of television and thermal imaging channels of the OESS with matrix detectors are given. The influence of focal length and of entrance pupil diameter of the lenses on the energy resolution was studied for observation distances from 0.5 km to 2 km. It is shown that, in OESS with variable magnification, lenses with a larger diameter of the entrance pupil are preferred - they provide more uniform energy sensitivity when changing the focal length. The developed calculation methods can be used for multispectral OESS operating in the visible and infrared spectrum ranges.