空间碎片天基探测相机光学系统设计

Optical system design of space-based detection camera of space debris

论述了空间碎片探测的方式和特点。通过讨论天基光学探测系统的应用要求,确定了系统的技术指标,实现了对亮度不小于六等星目标的探测,目标定位精度可达3.5″。通过分析,在设计过程中有效控制了视场内强光源形成的杂光影响,实现可同时观测亮暗目标的性能。系统焦距82 mm,入瞳直径70 mm,视场10°×10°,在450~900 nm谱段范围,2 600~9 800 K色温范围内,0.85视场内像点能量质心偏差优于3μm,各色温之间质心偏差优于1μm,2×2像元内弥散斑能量集中度不大于75%,3×3像元内弥散斑能量集中度不小于90%。采用遮光罩和镜头结构消除杂光,通过仿真分析表明在太阳抑制角大于50°时,系统PST不高于10^(-8)量级,可以满足暗目标观测要求。

The way and characteristics of space debris detection was analyzed. Based on the discussion of the requirements of space-based optical detection system, the system′ s technical specifications were presented. The detection of brightness higher than sixth-magnitude stars target was achieved, the target positioning precision could reach 3.5″. Through the analysis, the influence of stray light which produced of the strong light source in the field of view was controlled in the design process, and the performance of the bright and dark objects could be observed simultaneously. Technical specifications of optical system were ：82 mm effective focal length; 70 mm pupil diameter; 10°×10° field of view; under the condition of450-900 nm wavelength range, 2 600-9 800 K color temperature range, the deviation of energy centre is better than 3 μm in the field of view of 0.85, the deviation of energy centre between the various temperature color is better than 1 μm, meanwhile, spot diagram energy concentration is greater than 75%in the 2 ×2 pixel and the spot diagram energy concentration is not less than 90% in the 3 ×3 pixel. The requirements of dark targets observation can be met by the sun to suppress the angle is greater than 50 °,and the PST is not higher than 10^（-8）which are indicated by the simulation and analysis with the design of baffles and camera lens structures.