Patent ID: 6480273
Filing Date: 2002-11-12
Classification: G01J

Abstract:
A multispectral imaging system comprising:a multispectral imager for producing spatial pictures of an image scene in a plurality of different spectral wavelength bands; and an optical processor for simultaneously comparing an input wavelength spectrum observed in a scene image from said multispectral imager with a plurality of template wavelength spectra to find a correlation, said optical processor including: a first spatial light modulator having an array of modulating elements including n modulating elements arranged linearly for receiving respective ones of n spectral bands of an input wavelength spectrum observed in a scene image from said multispectral imager and independently altering at least one property of an incident light beam by a value corresponding to the observed intensity of the input spectrum in the respective spectral band; means for expanding a modulated beam of an input wavelength spectrum from said n elements of said first spatial light modulator in a spatial dimension perpendicular to the linear direction of said n elements thereof; and a second spatial light modulator having a two-dimensional array of nÃ—m modulating elements through which said expanded, modulated beam of an input wavelength spectrum from said n elements of said first spatial light modulator is transited, each row n of said nÃ—m array of elements altering said at least one property of the incident light by values corresponding to a particular template wavelength spectrum of m such template wavelength spectra of said two-dimensional array of elements of said second spatial light modulator, and wherein said values corresponding to each template spectrum of said m template spectra are the conjugates of said representative values of said n elements of said template spectrum of said m template spectra.