Research On The Signal-to-noise Ratio Of Large Aperture Static Imaging Spectrometer

Signal to noise ratio (SNR) is one of the most important parameters whichevaluate the performance of the spectral imagers. Especially for Large Aperture StaticImaging Spectrometry (LASIS), the instrument SNR evaluation appears to be evenmore crucial due to the intricate mathematical and physical process in data acquiring.At present, the mature SNR estimate method has been barely reported. This thesishappens to present a thorough analysis and mathematical model of the SNRevaluation of LASIS system. Furthermore, its theory is put into test by the dataacquired by practical devices designed for engineering purpose. The main contentsinclude:1. The basic concepts, category, development and applications of spectralimaging technology are briefly introduced. Moreover, the traditional SNR estimateand evaluation methods of spectral imager are given.2. The fundamental theory of interference spectral imager technology iselaborated. Three different means of modulation to acquire interference data isintroduced and, their basic principle and specialty are discussed. Furthermore, theSNR definition of different interference spectral imager is also presented.3. The interference theory of different type of spectral imager is analyzed. Bystudying the features of signal and noise, the theoretical models of both interferogramSNR and spectrum SNR of LASIS are established and, the model is put into test byreal data.4. From four aspects: beam splitter, detector, instrument calibration and dataprocessing, the author analyzes the factors that affect the SNR performance of LASISsystem and also give a elaborated qualitative or quantitative analysis.5. The SNR estimation of a LASIS prototype which is designed and assembled inour lab is given according to the forementioned SNR theoretical model. Moreover, thetesting method of the instrument is argued and put into practice. Comparing theresults of theoretical prediction and experiment the validity of the model is proved. The correlative SNR issues about LASIS are well studied in this thesis,especially in the aspect of establishing the SNR evaluation method. The theory andmathematical model are proved to be effective by experiment results. The SNRevaluation theory in the thesis has high academic value and will improve theengineering level of this type of instruments.