Analysis And Suppression Of Infrared Stray Light Of Geosynchronous Orbiting Telescope

The working environment temperature of geosynchronous orbiting telescope is complicated,and its environment temperature is very seriously affected by the sun.In order to improve the detection performance of the geosynchronous orbiting telescope for faint targets,the stray radiation of the telescope is suppressed to reduce the stray radiation from reaching the image surface of the system and improve the imaging quality of the telescope.Infrared stray light refers to the light that travels to the image surface of the optical system in addition to the target light.The hazard of infrared stray light is that it reduces the contrast and signal-to-noise ratio of the optical system's image plane,and reduces the quality of the target image.In severe cases,the thermal radiation energy generated by the infrared stray light will submerge the radiation energy of the earth target signal,and affect the detection ability and resolution of the system.This thesis studies the suppression and development of stray light in telescopes at home and abroad,and explains the role and importance of stray light suppression in the performance of the telescope system.The research work of the thesis mainly includes the following aspects.The article first summarizes the basic theories and basic laws of infrared stray light,sets specific parameters,and uses basic laws and formulas to explain that the sun's stray radiation has a large impact on the temperature change at the intermediate image plane's field stop and has a long acting time.The thermal radiation energy generated by stray light will submerge the radiation energy of the earth target signal.And the thermal simulation analysis verified the necessity of setting the "field stop heat dissipator" to suppress infrared stray radiation.Secondly,the sources and research methods of infrared stray light of the geosynchronous orbiting telescope system are analyzed,and the common methods of infrared stray radiation suppression are listed.In terms of the principle of the stray radiation suppression structure,the design method of the hood,the light-blocking ring and the stop is given,and the method of setting the internal optical components "field stop heat dissipator" is adopted to optimize the internal optical and mechanical structure of the telescope system,suppressing the stray radiation of the geosynchronous orbit infrared telescope system.These suppression methods have reference significance and application value for the design of actual suppression structures.Finally,according to the geosynchronous orbiting telescope system,specific infrared stray radiation suppression measures are proposed.Use Light Tools software to build a model and perform ray tracing simulation analysis,and calculate and compare the point source transmittance(PST)of the telescope system before and after the addition of the "field stop heat dissipator",and verify the suppression effect of the hood and light-blocking ring through thermal stray radiation simulation analysis,and evaluate the effectiveness of the stray radiation suppression measures.