Analysis Of Influence Of Opto-mechanical Structure Temperature On Detection Capability Of Space-based Infrared System

As an important part of space-based detection system,space-based infrared system is becoming more and more important in space early warning.The main factors limiting the detection capability of space-based infrared systems are detector performance and stray radiation.With the development of detector technology,the limitation of stray radiation on detection capability is increasing.Stray radiation is divided into external stray radiation and self-thermal radiation.With the continuous improvement of mechanical devices such as lens hood and Light blocking ring to suppress external stray radiation,the influence of self-thermal radiation of infrared system is gradually highlighted.Therefore,the analysis of the influence of the optical-mechanical structure temperature of the space-based infrared system on the detection capability is of great significance for the improvement of the detection capability of the system and the design of cold optics.Based on the analysis of the detection capability requirements of space-based infrared system,this paper analyzes the factors affecting self-thermal radiation of the opto-mechanical structure,establishes the analysis link between self-thermal radiation and detection capability index,and proposes the distributed detection capability analysis method in view of the non-uniformity of irradiance and detection capability distribution in the focal plane.Furthermore,the influence of self-thermal radiation of space-based infrared system on target detection capability is studied,and according to the detection capability index,more specific system refrigeration suggestions are proposed.The main content of this paper includes the following parts:1.Understand the research background,investigate and analyze the influence of domestic and foreign self-thermal radiation and detection ability,and summarize the research progress.2.Introduce the detection capability index of space-based infrared system and the theoretical analysis process of infrared system self-thermal radiation,and further give the calculation model of detection capability related to infrared system self-thermal radiation.3.In view of the regional distribution of focal plane of detection capability caused by the influence of self-thermal radiation and scene radiation,the analysis and calculation methods are proposed,and the zoning principle of subregion is discussed.4.To verify the distributed detection capability analysis method,the transmission optical system and reflective optical system were established respectively to analyze the self-thermal radiation of the opto-mechanical structure,and then the influence of self-thermal radiation of different components on the focal plane irradiance was discussed.The zonal principle used in this paper is determined and the zonal irradiance analysis of the focal plane of self-thermal radiation of the transmission and reflective optical system is carried out.5.Comparative analysis is made on the influence of transmission and reflection opto-mechanical structure on the overall detection capability of focal plane and the influence of regional detection capability.By comparing and analyzing the refrigeration of the main influence surfaces,the best choice of the system refrigeration components and the refrigeration temperature is obtained through the given detection capability requirements.Therefore,the main influence surface of the analysis area can be obtained by the distributed detection capability analysis method to achieve the detection capability improvement demand,which is more targeted.In summary,through theoretical research and simulation analysis,this paper establishes a calculation model,proposes a distributed detection capability analysis method,analyzes and studies the influence of opto-mechanical structure temperature on detection capability,and provides a basis for subsequent relevant research work.