ANALYSIS OF OPTICAL SYSTEMS OF POLARIMETRIC THERMAL IMAGERS

Polarimetric thermal imagers are essential tools in modern detection and observation systems, enabling the acquisition of object images by measuring the polarization characteristics of infrared radiation. This opens new opportunities for improving image contrast and resolution under low-visibility conditions. The problem lies in the fact that optimizing the optical systems of such thermal imagers remains a challenging task due to the complexity of the physical processes involved, necessitating additional analysis and modelling. A review of recent studies and publications shows that numerous works are dedicated to the application of thermal imagers in detection and recognition systems, as well as to methods for assessing their resolution. In particular, V. H. Kolobrodov emphasizes the need for improving the optical characteristics of thermal imagers, while G. C. Holst proposes methods for calculating the modulation transfer function (MTF). Some studies focus on modelling optical systems using modern software tools. However, the issue of optimizing the optical systems of polarimetric thermal imagers remains relevant. The aim of this work is to conduct a theoretical analysis of optical systems of polarimetric thermal imagers, analyse mathematical models describing the operation of such systems, perform modelling of optical systems using the Python programming environment, and provide recommendations for optimizing optical systems to enhance their characteristics. The results include an examination of the energetic and spatial characteristics of object and background radiation, as well as the transmission of infrared radiation through the atmosphere. Mathematical models describing the operation of optical systems are presented, including formulas for calculating the MTF and the minimum resolvable temperature difference (MRTD). Modelling of optical systems and polarization effects was performed using the Python programming environment. The modelling results are presented in the form of graphs and tables. The conclusions indicate that the obtained results can be used in the development of new thermal imaging devices with improved characteristics. It has been determined that accounting for polarization effects and optimizing optical components can enhance the resolution and sensitivity of thermal imagers. Prospects for further research include experimental verification of the proposed models and the development of image processing algorithms that incorporate polarization characteristics.