Research On Encoding Mask In Hadamard Transform Spectrometer

The thesis begins with analyzing the specialties of weak radiant detection and its elementary demands for spectrometer- multichannel detection. Analyzing and comparing various existing multichannel spectrometry and its instrument, the potentiality of HT imaging spectrometry based on mask modulation and single element detector in weak radiant detection is expounded in detail .The recent developments and research level at home and abroad in HT spectrometry and its instrument are systematically summarized. Secondly, a three dimensional image-spectrum function, which characterizes the measured, is proposed, and then the encoding mathematical model of HT imaging spectrometry is established and the concrete methods to recover image-spectrum information are provided. Thirdly, the methods to determine and to construct encoding matrix are discussed. Fourthly, the effect of the uniform defects of mask's transparency on the signal-to-noise ratio of encoding measurement is analyzed theoretically, and the relational expression between them is presented, which provides a criteria for judging the mask quality. Fifth, a study of LC-SLM used as a stationary encoding mask of HT spectrometer. Sixth, A fast and accurate decoding method is proposed is given. A measure of compensating for the defect is proposed.