机载红外推扫成像光谱仪光学设计

红外成像光谱仪适用于火山活动探测、森林火灾监测、城市化影响分析、地球表面研究及军事伪装识别等方面。文中基于Dyson 中继系统，设计使用波长范围为7.5~10 m 的长波红外成像光谱仪，采用凹面衍射光栅分光，系统F 数达到1.2，视场角18，空间分辨率为1 mrad，光谱分辨率为50 nm，NETD 小于0.3 K,调制传递函数接近衍射极限，光学系统体积为72 mm39 mm39 mm。该系统具有集光本领强、固有像差小、结构紧凑等优点。对其杂散热辐射分析表明，采用实入瞳作为冷光栏和整体制冷的方法，能有效地抑制光机系统自身的热辐射。

Optical design of airborne infrared pushbroom imaging spectrometer

Infrared imaging spectrometers are applied to volcano behavior detection, forest fire survey, urbanization effect analysis, terrestrial composition and change monitoring, and camouflage recognition. In this paper, based on Dyson relay, a long wave infrared imaging spectrometer with wavelength range of 7.5 to 10 m was designed, which used a concave diffraction grating as its dispersive element. Its F number reached 1.2, field angle of view was 18 and spatial pixel resolution was 1 mrad, spectral resolution was 50 nm and noise equivalent temperature difference (NETD) was less than 0.3 K. The size of this designed optical system was about 72 mm39 mm39 mm, and its modulation transfer function approached to diffraction limitation. It has advantages of high throughput, low inherent aberration, and compactness. Analysis of its stray thermal radiation shows that its own thermal radiation of optical- mechanical system can be effectively suppressed by use of real entrance pupil as cool stop and of cryogenic optics.