Study On UV-VIS Spectral Imaging Technique With High Resolution

Ultraviolet and visible (UV-VIS) spectral imaging technology is an importantpart of aviation and aerospace remote sensing technology, meanwhile, a large field ofview, wide spectral range and high-resolution is the main development direction ofimaging spectrometer technology. Compared with the international advanced level，our study on UV-VIS imaging spectrum technology started late. The paper carriedout a airborne UV-VIS spectral imaging spectroscopy, with the spectral range from310nm to500nm, spectral resolution from0.3nm to0.5nm, spatial angle resolutionof0.5mrad, the total field of view angle of14°, and designed a larger field of view,wider spectral range, high spatial and spectral resolution UV-VIS spectral imagingspectroscopy. Some achievements have been obtained.First， based on the characteristics of UV-VIS spectral imaging technology, asymmetrical and coma-compensation Czerny-Turner reflective grating spectrometeris selected as the spectroscopic system, and a back-illuminated thinned area arrayCCD (BTCCD) as the detector device. Ground reflection, solar radiation andatmospheric scattering radiation on12km flight height are simulated. The equivalentelectron SNR estimation function is established, and some imaging methods, such asthe push-broom, linear whiskbroom,16line array TDI whiskbroom, andSBUV-ICCD push-broom, approaches to specific estimates. Finally, the spectralrange and numerical aperture of push-broom imaging spectrometer, which meetsSNR requirement, is determined.Second, an off-axis two-mirror concentric system is designed as thepre-telescope objective. On the basis of the systematic research on aberrationcorrection theory of Czerny-Turner spectrometer without auxiliary optics,convergent illumination anastigmatic theory of Czerny-Turner imaging spectrometeris proposed. It is given the distinguishes and scopes of application between thedivergent and convergent illumination astigmatism correction conditions andexperimental verifications, which provide a strong technical support to structuraloptimization and structure chosen of Czerny-Turner spectrometer without auxiliaryoptics.Third, according to the technical indicators requirements, a traditional1:1 Czerny-Turner spectral imaging system with a one-pixel width slit is designed,however, the image quality is not ideal over the whole large field of view. Then thenovel imaging spectrometer system with two-pixel width slit and the magnificationof1:2is designed and improve the image quality of edge field, through adjusting thegrating constant and the linear dispersion rate.Airborne UV-VIS imaging spectrometer design principle is the product ofdomestic and foreign advanced technology development, able to provide thenecessary technical support for further airborne and spaceborne engineeringprototype development.