针对中高层大气OH自由基的星载探测应用,给出一种基于空间外差光谱技术的临边探测方案。借助卫星平台的运动,呈正交布置的双通道光谱仪可以分时获取同一区域的一系列视线观测辐亮度,最终反演OH自由基数密度的三维分布。每个通道均包含柱面望远、准直镜头、一体化空间干涉组件和成像镜头,可以同时探测不同高度层的OH自由基辐亮度,具有光通量大、结构稳定、小型化等特点。以紫外波段(308.2~309.8 nm)和光谱分辨率优于0.01 nm的要求进行中高层大气OH自由基临边探测为例,给出了光学系统设计的过程和结果,并利用太阳跟踪器进行了地基太阳光谱观测实验。结果表明:光学系统设计可满足探测指标的要求,实测太阳光谱与理论光谱特征一致性较好,为星载中高层大气遥感探测技术提供了参考。

A hyper-resolution spatial heterodyne spectrometer (SHS) used for hydroxyl radical OH detection with limb observations from a satellite is presented. The SHS instrument, consisting of two 1-D imaging channels in two orthogonal observation directions at different time for the same volume with the aid of the movement of the satellite platform, can get the three-dimensional distribution of OH with a series of observation radiation intensities. Each channel, including cylindrical telescope, collimating lens, a monolithic spatial interference unit and imaging lens, has vertical spatial resolution without scanning parts, and it can be field widened with prisms in the interferometer arms to increase the throughout of the instrument. An optical system for measuring mesospheric OH with a spectral resolution of 0.01 nm over the 1.6 nm ultraviolet passband 308.2-309.8 nm is designed, and its optimizing process and results are shown. The ground-based experiment with the prototype instrument is carried out with the use of the light from the sun tracker. The measurement results show that the optical system design meet the needs of OH detection requirements, and the instrument experimental performances are in agreement with the theoretical spectral characteristics. Our research provides a basis for remote sensing of mesospheric atmosphere detection in satellite.