Research On The Fourier Transform Imaging Spectrometer Of Wide Swath For The Ocean Spectrum

Imaging Spectrometry is used to locate and identify the target and analyze its component by the obtained data cube which contains the images and the spectra of the target.Because of the characters and advantages of the obtained data,Imaging Spectrometry has the great uses in the ocean science and detection.With the development of the application requirements,the broad field of view and the wide swath distance has become the future trend of the Imaging Spectrometry.In order to meet the demand of the ocean detection and the growing trend of the Imaging Spectrometry,this thesis presents a new Fourier Transform Imaging Spectrometer of wide swath based on the Image Plane Interference for the application of ocean spectrum.The associated researches and results of this thesis are stated as the following:1.The concepts and the classification of the Fourier Transform Imaging Spectrometry are briefly introduced.The applications of Fourier Transform Imaging Spectrometry in the Ocean Spectrum are studied.And the research results and status of Fourier Transform Imaging Spectrometry are analyzed and summarized.2.The basic principles and theories of the Fourier Imaging Spectroscopy are briefly introduced.The theory of the image plane interferometer is studied.The image plane interferometer has the ability to broaden the field of view of the imaging spectrometer.The reason of the ability to widen the swath is studied.3.The technical plan of this thesis is presented.The interferometer of the imaging spectrometer is designed and the equation of the optical path difference of the interferometer is deduced and calculated.System parameters are designed and calculated based on the demand of the ocean detection.The computation model of the Signal to Noise Ratio is studied and calculated,which is an important parameter of the imaging spectrometer.According to the study,the swath width of the system is 320 km.The spectral range is 400-900 nm while the spectral resolution of the system is 5 nm.The average of the SNR is 120 based on the computation model of the Fourier Transform Imaging Spectrometer.4.Based on system parameters which are presented in the previous thesis,the optical system of the Fourier Transform Imaging Spectrometer is designed and optimized.The optical system is composed by the fore optics and the relay lens.The fore optics is designed based on the complicated Double Gauss Objective and the relay lens is designed based on the modified Dyson System.According to the design,at 35.5o FOV and 400-900 nm spectral range,the MTF of the optical system is superior to 0.5 at the Nyquist frequency.The parameters and the demand of the optical system are fully accomplished.5.The nonlinear interference error which is generated in the interferometer of the system is studied and the spectrum reconstruction algorithm of the nonlinear interference error is presented.Based on the two different fitting modes of the index of the refraction the spectrum of the target is reconstructed and the nonlinear interference error is removed.