Reference input patterns for evaluation and alignment of an optical matched filter correlator

Claim 1

A reference input pattern providing for evaluation and alignment of an optical instrument which optically compares an input image with optical information stored in an array of a plurality of matched filters to provide identification and aspect information about the input image, wherein an input image to be analyzed is spatially modulated onto a reference beam of radiation, and is directed onto a plurality of lenses to obtain a plurality of Fourier transforms of the spatially modulated radiation beam, and an optical memory element having an array of a plurality matched filters recorded thereon, and having the plurality of Fourier transforms incident thereon, with each matched filter comprising a Fourier transform hologram of an aspect view of an object of interest and passing an optical correlation signal in dependence upon the degree of correlation of the Fourier transform of the spatially modulated radiation beam with the Fourier transform hologram recorded by the matched filter, an inverse Fourier transform lens means receiving the optical correlation outputs of the matched filters, for performing an inverse Fourier transformation on each optical correlation output, and a detector means for detecting the inverse Fourier transforms of the optical correlation outputs, and for producing detector output signals representative of the optical correlation outputs; said reference input pattern supplying said input image to the optical instrument and providing for evaluation and alignment of said optical instrument, and comprising a two dimensional array of substantially transparent reference targets provided on a uniform dark background which provides an identifiable power spectral density distribution and autocorrelation function, for evaluation and alignment of the optical instrument.