反射式椭球面光栏在空间光学遥感器上的应用

摘要

For the purpose of suppressing the external stray light from the sun, earth and atmosphere, a cyclical grating system is traditionally used on baffle inner wall. The traditional cyclical grating system with high absorptance enlarges the blackbody area at entrance, and causes its and baffle’s temperature extremely high when baffle inner wall is illuminated directly by sunshine. This has negative impact on temperature stability of space camera near baffle and induces extra stray infrared light. To eliminate the defects of traditional cyclical grating system, a reflective ellipsoid grating system is designed in this paper. The thermal analysis soft code UG NX is used to modeling the heat load and stray light distribution of traditional cyclical grating system and the reflective ellipsoid grating system in the flight environment on geostationary orbit respectively. The simulation results indicate that compared with the traditional grating system, the reflective ellipsoid grating system can eliminate stray light from the sun, earth and atmosphere, and can decrease heat load of entrance by 60%~70%, which can avoid the baffle’s extremely high temperature.%空间光学遥感器遮光罩内壁通常会布置消除太阳、地气等外部杂散光的环状光栏，而传统的高吸收率直环环状光栏会显著加大光学系统入光口的黑体面积，尤其在高热流密度的阳光直射遮光罩内壁时，会导致遮光罩内壁及光栏自身温度出现极端高温现象，进而对光学系统前光学镜头的温度稳定度带来负面影响，同时引入了额外的内部红外谱段杂散光。为消除上述弊端，文章给出了一种反射式椭球面光栏的设计方案。针对地球静止轨道遥感器在轨飞行环境及入光口特征，采用UG NX热分析软件建立了热仿真模型，并通过软件中的蒙特卡罗法统计、对比了该反射式椭球面光栏与传统直环光栏的热负荷及杂散光分布情况。结果表明，相比传统光栏，该反射式椭球面光栏在有效消除太阳、地气等外部杂散光的同时，可以将遥感器入光口的热负荷降低60%~70%，避免了入光口的极端高温现象。