Research On Key Technology Of Prism-Grating Short-Wave Infrared Imaging Spectrometer

Imaging spectrometer is the combination of optical imaging technology and spectral analysis technology.It can acquire the image information and its corresponding spectral information of the target.The contradiction between imaging and spectrum is well coordinated by the introduction of slit.The image information and spectral information of the target can be collected at the same time.Thus the imaging spectral data cube of the target can be obtained.From the data cube,the spatial image and the corresponding spectral curve of any position in the spatial image can be extracted.That is to say,the fusion of imaging technology and spectral technology is realized.At present,imaging spectrometer has been widely used in aerospace remote sensing,medical detection and diagnosis,mineral resources exploration,environmental monitoring,military reconnaissance and camouflage recognition and many other fields.With the continuous promotion of imaging spectroscopy technology in China,the application demand of imaging spectroscopy which can cover the complete solar reflection spectrum region has become increasingly strong.With the rapid development of UAV technology in recent years,the demand of miniaturized portable short-wave infrared imaging spectrometer for UAV has become a trend.In view of this,the research on prism-grating short-wave infrared imaging spectrometer is carried out in this paper.The aim is to develop a short-wave infrared imaging spectrometer with independent intellectual property rights.Aiming at some key problems in the design,fabrication and adjustment of prism-grating short-wave infrared imaging spectrometer,the key technology of developing prism-grating short-wave infrared imaging spectrometer is broken through.The main contents of this paper are as follows:1.Design of Optical System for Prism-Grating Short Wave Infrared Imaging Spectrometer.Firstly,the design of short-wave infrared prism-grating dispersion module is completed.Based on the prism-grating module,the optical system of the short-wave infrared imaging spectrometer is designed,including the design of the short-wave infrared image telescope system,the design of the prism-grating dispersion system and the integrated combination optimization of the telescope system and the dispersion system.The rigorous tolerance analysis and distribution of the optical system ensure the feasibility of the whole optical system processing and adjustment.2.Research on Detector Correction Technology of Short-Wave Infrared Imaging Spectrometer.In order to solve the problem of bad pixels and non-uniformity of response in short-wave infrared detectors,a set of correction schemes is proposed,which are used to correct bad pixels and non-uniformity in turn for short-wave infrared detectors.According to the application background of imaging spectroscopy technology,the bad pixels are corrected by means of spectral two-neighborhood mean substitution,and the non-uniformity of detector is corrected by two-point method with less computation and faster calculation speed.By correcting the detector,the quality of the data acquired by the detector is improved,thus ensuring that the instrument can acquire high quality imaging spectral data.3.Research on Adjustment Technology of Prism-Grating Short-Wave Infrared Imaging Spectrometer.In order to solve the problem of adjusting the invisible short-wave infrared optical system,a method of 632.8 nm assisted adjusting is proposed.To a certain extent,the imaging quality of the auxiliary light can be used to ensure the imaging quality of the working band.Among them,telescope system module,prism-grating spectroscopy module and the front and back modules of the spectroscopy system are independently assembled and adjusted by modularization idea,and then combined with detectors to carry out the whole machine debugging,which ensures that the performance of the instrument achieves the desired design results.4.Spectral Calibration and Instrument Testing of Prism-Grating Short-Wave Infrared Imaging Spectrometer.The spectral calibration system of prism-grating short-wave infrared imaging spectrometer is designed and built,including calibration light source,wide-band high-resolution calibration monochrometer system,collimator and spectral calibration curve fitting algorithm.The spectral response function and spectral resolution of the instrument were tested,and the spectral calibration of the whole working band of the instrument was completed.The instrument is tested and the performance of acquiring imaging spectral data is verified by experiments on specific targets.