A new method in imaging spectrometry

摘要

This new technique for imaging spectrometry is based on computed-tomography (CT). The obvious feature of this method comparing with other imaging spectrometry is its optical system. Two cylindrical lenses compress a two-dimensional object into a one-dimensional image. Subsequently, the spectral image dispersed by a grating is obtained by two-dimensional detector array. A rotation scanning could collect a series of spectral images with different projection angles. The spectral image of the object is reconstructed from these projection images by computed-tomography algorithm. Although this method still needs a rotation scanning to obtain enough information for giving out the data cube of the object, its energy efficiency, and its signal to noise, could be improved significantly. The optical and mathematical theories of this method are discussed. And the suggested optical configuration has also given. A discrete model of this imaging spectrometric system is established to show the digital reconstruction algorithms. A computer simulation based on the discrete model is executed by MATLAB. The reconstructed results with a defined spectral image indicate that the method is capable of reconstructing scenes containing both broadband samples and narrow-band samples. When the specific noise is added, the impact of the number of projection angles on reconstruction precision is analyzed.