Acoustic Signal Optical Correlator Using a Light Emitting Diode Array.
Patent, Filed 1 May 86, patented 14 Feb 89,
DEPARTMENT OF THE NAVY WASHINGTON DC
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An optical correlator using a light emitting diode array, in which analog signals from two spaced sensors are correlated in order to locate and track a target. One signal is clipped and digitized and clocked through a shift register, and the other signal is delayed. The shift register is coupled to an LED array, element for element. Each shift register element modulates its corresponding LED element. The delayed signal is also connected at its output to the LED array via a transistor, and modulates each LED element. Therefore, the LED elements emit light in proportion to the product of the two signals. The emitted light is focused onto a CCD imaging array where it is integrated over a period of time before being sent to an integrator and output display device. The output is the correlation function versus the time delay between the two signals. Successive outputs display the movement of targets. Circuit design mitigates inherent errors within the system. Patents. rh