摘要
为了确定超光谱成像仪热控指标和开展热设计,研究了超光谱成像仪中棱镜的热光谱特性。介绍了超光谱成像仪的工作原理以及热光谱特性的含义,分析了棱镜的环境热效应,论述了棱镜热光谱特性研究内容及技术路线,推导了温度变化时棱镜偏转角以及角色散的函数关系,进一步得到光谱中心平移及光谱带宽随温度变化规律。借助有限元分析,比较了K9、熔石英两种材料的棱镜的入射角、顶角、材料色散、光谱中心平移及光谱带宽随温度变化规律,确定了棱镜的热控指标,并设计了热光谱试验。理论分析和试验结果表明由于热变形引起的光谱带宽和光谱分辨率改变可以忽略不计,光谱平移主要由材料折射率温度系数决定;棱镜材料色散(dn/dλ)对温度变化不敏感,因此温度变化对其光谱带宽影响不明显;本文研究方法合理,结果可信,对确定棱镜的热控指标和优化热设计具有指导意义。
Prism is one of the most key parts in the hyper spectral imager （HSI）.Consequently,to set thermal control target and make thermal control design,the thermal spectral property of prism in the HSI was studied.The working principle of the HSI and the definition of its thermal spectral property were introduced.The working environment of prism and its thermal effect were analyzed;also the study contents and technical route of the prism’s thermal spectral property were discussed.The effects of different uniform temperature field on deflexion angle and angular dispersion of the prism in the HSI were deduced,and the changes in displacement of the spectra and the spectral bandwidth under different uniform temperature were obtained.For one instance,the thermal spectral property of the K9 prism and the fused silica prism were compared based on FEM and combined experiments,furthermore,its thermal control target was ascertained and a thermal spectral property test was carried out to validate the rationality of the thermal spectral property analysis.The results of analysis indicated that the changes in spectral bandwidth and spectrum resolution brought by thermal distortions can be ignored according to current fixing mode,and the displacement of the spectra is mainly determined by thermal coefficient of material refractive index;because of it’s the lower thermal coefficient of material refractive index,the displacement of the spectra of the K9 prism is smaller under the same temperature changes;the material deflexion changes （dn/dλ） of prism are not sensitive to the temperature,so the changes in spectral bandwidth caused by them are not obvious.And the results of test proved that the studied method of thermal spectral property is reasonable and essential,and the results are authentic and credible.So it can provide some guidance for setting thermal control target and optimizing thermal control design.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2010年第6期1702-1706,共5页
Spectroscopy and Spectral Analysis
基金
中国科学院"优秀博士学位论文
院长奖学金获得者科研启动专项基金"项目资助
关键词
超光谱成像仪
棱镜
热光谱特性
光谱带宽
光谱分辨率
Hyper spectral imager
Prism
Thermal spectral property
Spectral bandwidth
Spectral resolution
