Portable real-time coherent optical correlator

A real-time coherent optical correlator is mounted inside a 15- x 23- x 38-cm enclosure and features laser diode light sources and a liquid crystal incoherent-to-coherent image converter. Each of four reference filters is illuminated by a separate laser diode, real-time operation is achieved by the image converter, and a zoom lens forming the incoherent image allows a scale search. The correlator can be mounted on a tripod and performs correlations indoors or outdoors.