Real Time Correlation for Missile Terminal Guidance.

Abstract : A study was conducted to determine the feasibility of using coherent optical correlators for missile terminal guidance. A laboratory area correlator was built which can perform target recognition and location at TV frame rates. This correlator uses an optically addressed liquid crystal image-forming light modulator as an input and holographic matched filters as references. Correlations were performed with optical imagery and simulated radar imagery using a TV monitor to address the modulator. Good cross-correlation signal-to-noise ratios were obtained and the input image could be tracked over a wide displacement range. Data from these experiments were used to design a compact correlator for typical low resolution radar imagery. The low informaton content of this imagery allows an array of laser diode sources to be used. By using a corresponding array of matched filter references, up to 900 correlations/second can be performed on 128 x 128 element input imagery and a range of scale, angular orientation, or aspect angle can be searched. (Author)