The Study On Full-field And Automatic Methodology Of Spectral Calibration For Imaging Spectrometers

Imaging spectrometer can obtain the image information and spectral curveinformation at the same time, there are many important applications in the chemicalindustry, metallurgy, military, scientific, astronomy and other fields. Imagingspectrometer performance will be infected by the application environment, such asweather and many other effects caused by environment changes. Measurement dataalso needs to be analysis depends on the results of spectral calibration, and reach thetarget which distinguishes the object features.Spectral calibration is an important means to determine the spectralcharacteristics of imaging spectrometer, such as spectral response function, spectralrange, the center wavelength of the spectral channels, spectral resolution, spectralbend ("smile") and so on. This paper investigates the typical spectral imagingspectrometer calibration system, and discusses the advantages and disadvantages ofvarious calibration systems. Analyzed has been done about the principle of spectralcalibration theoretical depend on the push-broom imaging spectrometer imagingtheory. Use monochromatic collimated light method designed a push-broom imagingspectrometer spectral calibration system with full field and automated, whichincludes a light source system, monochromator system, collimated light system andfield scanning system. Design a monochromator which is applied in spectral calibration system. The monochromatic collimated light system introduce a sphericalmirror provides collimated light, and use a freely sliding and rotating folding mirrorchanges the angle of incidence light,in order to realize full-field and automaticcalibration of imaging spectrometer. The optical simulations of the spectralcalibration system have been done, which certify reliability of the overall system.The mechanical structure of the spectral calibration is proposed based on opticalsimulation results.A set of hardware architecture of automatic spectral calibration system withimaging spectrometer have been established, Include light source, monochromator,field scanning system and data acquisition system. Programs about automatedspectral calibration have been completed with LabVIEW, and realize the automationof entire spectral calibration system. Experiments of spectral calibration for PGPimaging spectrometer and accuracy analysis combined with the structural features ofthe entire spectral calibration system have been done.The calibration system has merits of small size, better commonality, and highprecision and so on, and can be used for spectral calibration of other imagingspectrometers whose structures are similar to PGP.