Research Of Noise Reduction Technique In Imaging Spectrometer With Grating Dispersion

Spectral imaging is a newly integrated technology, which is involved in spectrum analysis and image processing. It can not only access the spatial image information of the target, but also to obtain the spectral information of the target. It solves the problem of "no spectral imaging" and "non-spectral imaging" in the traditional fields of optical science.Imaging spectrometer can obtain more information, so it has been widely applied in many fields, such as geology, oceanography, agriculture, forestry, hydrology, urban, environmental, military and so on. In the development process, dispersion type imaging spectrometers was earliest and the technology was more mature. In which the grating with high spectral resolution, small size, many advantages was widely used. It used in the detection range of far distant receiving the objective, receiving target radiation energy is weak,and imaging process has join in all kinds of noise, make reduces the detection capability of the instrument.In this paper, the analysis and research of noise reduction of imaging spectrometer with Grating Dispersion, for noise reduction to improve the instrument. Including the following aspects:1 According to the mechanism of hyperspectral imagery, analysis to join in the work process of the imaging spectrometer noise.2 Imaging spectrometer telescope system was often used R-C system. R-C system is that out-of-field stray light may straight arrive at the detector without any scattering, so as to damage the image quality. At first, the baffle and Vane was designed. Secondly, the solid model of the R-C system is constructed in Tracepro software, and then the Point Sources Transmittance is calculated at some different off axis angle between 0.5～40degree. The experiments show that the spectral stray light signal is basically down to be corrected to zero.3 According to the characteristics of the stray light in the grating spectrometer system.The line spread function of spectrometer is characterized by a He-Ne laser. Assuming that the spectrometer is a wavelength invariably system. Spectral distribution matrix is constructed by the derived line spread function, then the bandwidth correction of wavelength with bandwidth correction matrix. Finally, the experiment results prove the stray light correction of imaging spectrometer.