Study On Imaging Spectrum Reconstruction Algorithm Of Spatial Heterodyne Imaging Spectrometer

Spatial heterodyne scanning imaging spectrum combines the advantages of spatial heterodyne spectroscopy and imaging technology.It can obtain the image and the spectral information with the characteristics of high spectral resolution,high flux and small volume.It can achieve spectral restoration of all the target points in the measured area through scan imaging one time only.It plays an important role in the fields of hyperspectral resolution remote sensing detection,national territory monitoring and earth atmosphere composition detection.How to realize the transformation from interference images to spectral information is the key to the role of the spatial heterodyne imaging spectrometer.It is very important to recover spectral information accurately and efficiently.In this paper,based on spatial heterodyne spectroscopy technology,the scanning imaging principle and interference information distribution are deeply studied,then the spectrum reconstruction algorithm of spatial heterodyne imaging spectrometer is constructed,aiming at solving the inversion problem of reconstructing spectral information by the original interference images.First of all,in order to be able to extract the interference information accurately in the algorithm of the interference information extraction.The distribution of interference information in interference images and the acquisition principle of interference image sequences are studied.The basic theory of spatial heterodyne spectroscopy and the scheme of scanning imaging are also studied.The model of spatial heterodyne spectrometer is established by ZEMAX and MTALAB.With monochromatic light source and potassium atomic line source as the input light sources,the system outputs the interference image,and the spectrum of incident light is recovered by Fourier transform.So,the feasibility of the instrument model of spatial heterodyne spectrometer is verified.Then,based on the principle of interference information distr ibution,the algorithm of structuring spectrum is generated,including image preprocessing,image registration,information extraction and spectrum recovery.In addition,the data structure of spectrum cube is given.Finally,the high precision scanning platform is built to carry out the experiment of the spatial heterodyne scanning imaging.The validity and reliability of the spectrum reconstruction algorithm of spatial heterodyne imaging spectrometer are verified.The potassium atomic line source,xenon light source and tungsten light source are used to simulate the light source.The image sequences are collected and then the spectrum cube is calculated by the algorithm of spectral restoration.In order to reduce the displacement error in the scanning process of the system,SURF(speed-up Robust Features)algorithm is used for image registration to improve the reconstruction accuracy of data.The spectral information obtained from the spatial heterodyne spectrometer is consistent with the reference spectral information obtained by the optical fiber spectrometer,which verifies the feasibility and reliability of the algorithm of spectral restoration.The results show that the algorithm of spectral restoration based on the principle of spatial heterodyne scanning imaging can realize the reconstruction from the original interferogram to the spectrum cube.The method of image registration can correct displacement error of system scan to improve the accuracy of spectral restoration.Finally,the spectrum data cube can be used to realize the fast detection of regional target spectrum.