Abstract: Be restricted within the narrow space, missileborne infrared thermograph integrates the electrical，optical and mechanical components in limited space． The imaging quality of thermograph and detector capability will be affected by the heat dissipation of internal components and the external heat flux conducted by mechanical parts． Thermal design is needed to guarantee its normal work and high imaging quality in outer space． In this paper thermal design was taken according to the thermal environment and the structure characteristic of the thermograph. Passive control methods were used to extend the thermal time constant. The heat transfer model was built, and the simulation was taken based on the thermal control methods and the work condition. The analysis results showed that the temperature of thermograph was between 10℃~60℃, which met the thermal control index. Through the analysis, a warrant for reliability of thermograph and optimization of thermal design was provided.

Key words: Infrared thermograph, Thermal design, Thermal analysis