机载海洋改进型Dyson高光谱成像仪的研制

针对海洋环境、海洋水色等领域的发展需要,设计了一种适于机载的宽视场、大相对孔径的改进型Dyson光谱成像系统。根据海洋环境污染的光学特性,利用不同目标反照率值估算目标信号的信噪比,将高光谱成像仪的工作波段扩宽至紫外波段;使用大像元尺寸的探测器、大相对孔径的成像系统来满足对海洋目标弱信号的识别,同时通过降低积分时间来避免近海岸沙滩信号过强引起的探测器饱和。该光谱仪的工作波段为0.32~1.05μm、相对孔径为f/1.8、像元尺寸为24μm×24μm,通过加入弯月形的矫正镜避免了狭缝、探测器、滤光片和单透镜相互之间产生干涉。设计结果表明,整个光学系统各波长的传递函数均大于0.83,谱线弯曲和谱带弯曲均小于像元尺寸的4%。所设计成像光谱仪系统适用于海洋环境污染,尤其是海洋溢油污染的监测。

Development of airborne ocean modified Dyson hyperspectral imager

Aiming at development requirements of marine environment,ocean color and other fields,an airborne improved Dyson spectral imaging system with wide field of view and large relative aperture was designed.According to optical properties of marine environmental pollution,albedo value of different targets was used to estimate the signal-to-noise ratio(SNR)of target signal for expanding the working waveband of the hyper-spectral imager to the ultraviolet.A detector with large pixel size and an imaging system with large relative aperture were employed for the identification of weak signal of marine target;meanwhile,integration time was reduced to avoid detector saturation caused by excessively strong signals from inshore sand beach.The working waveband of the spectrometer was 0.32~1.05 μm with relative aperture of f/1.8 and pixel size of 24 μm×24 μm.Mutual interferences among slit,detector,optical filter and single lens were avoided through adding falcate correction lens.The design result shows that the optical transfer function at all wavelengths of the whole optical system is more than 0.83.In addition,both the smile and the keystone are less than 4% of pixel size.The designed imaging spectrometer is applicable to monitor marine environmental pollutions,especially marine oil pollution.