Patent ID: 6323972
Filing Date: 2001-11-27
Classification: G03H,G06K

Abstract:
A real-time analog creation of holographic Fourier transform matched filters comprising:(A) a first subsystem (10 A) which comprises a laser light source, a keyhole, a first lens, and a first beamsplitter, said laser light source producing a coherent monochromatic light which is received and expanded by said keyhole, said keyhole outputting said expanded light to said first lens collimating said expanded light and outputting said collimated light to a first beamsplitter, said first beamsplitter dividing said collimated light into an object wave of light and a reference wave of light;(B) a second subsystem (10 B) which comprises a first mirror, a rotatable second mirror, a third beamsplitter, and a first detector, said first mirror receiving said reference wave of light and transmitting same to said rotatable mirror which outputs said reference wave to a third beamsplitter which allows said reference wave to strike an element of a first detector at a slight angle thus providing the needed phase wedge for interference with Fourier transform of subsequently supplied input scene;(C) a third subsystem (10 C) which comprises a first spatial light modulator, a second lens, a second beamsplitter, a source for an input image which can be supplies by a camera, a computer, or other video equipment, and an input image, said first spatial light modulator receiving an input image from said source for an input image and outputting to said second lens that performs the Fourier transform of the input image and said second beamsplitter which outputs a portion of said object wave and said Fourier transform of input image to strike element of first detector, and said portion of output wave also being transferred to a second light modulator;(D) a fourth subsystem (10 D) which comprises a first computer for storing an array of information via a framegrabber, a second light modulator for receiving input from said first computer, a third lens that Fourier transforms the field transmitted by said second light modulator as combined with correlation point, and a second detector where correlation is produced;(E) A fifth subsystem (10 E) which comprises a beam block that blocks waves transmitted from said third beamsplitter that are not transmitted to detector; and,(F) A sixth subsystem (10 F) which comprises a second computer which stores the correlation produced at said second detector.