Abstract: A method and apparatus for discriminating digital data received from a plurality of spatially distinct acoustic sensing nodes of a distributed undersea optical surveillance system. The present invention advantageously employs Code Division Multiplexing (CDM), which is a synchronous variation of Code Division Multiple Access (CDMA), to communicate a plurality of digital data bit-streams from the nodes to a common location remote therefrom. The inventive system generates at the remote location a pseudo-random reference signal that functions as a carrier for communicating sensed acoustic data from the nodes to the remote location. Using the known spatial relationship between the nodes and the remote location and the pseudo-random reference signal, the present invention operatively synchronizes correlators at the remote location to receive and differentiate data from the various individual nodes.