Acoustic signal optical correlator using a light emitting diode array

An optical correlator using a light emitting diode array is presented 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 a light emitting diode (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 charge coupled device (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.