DISCRETE NON-LINEAR ASW DATA FUSION FOR SHALLOW WATER TRACKING AND SURVEILLANCE

CONTINGENCY AND LIMITED OBJECTIVE WARFARE OPERATIONS MAY REQUIRE NAVAL FORCES TO OPERATE CLOSE TO ENEMY SHORES IN SHALLOW WATERS WITH ADVERSE ACOUSTIC ENVIRONMENTS. THE OBJECTIVE OF THE PROPOSED WORK IS THE DEVELOPMENT OF A DATA FUSION SYSTEM THAT PROVIDES TRACKING AND SURVEILLANCE IN THIS ENVIRONMENT EVEN AGAINST DIESEL THREATS. SUCH A SYSTEM WILL REQUIRE THE USE OF MULTIPLE SOURCES AND RECEIVING ARRAYS. PRESENT DAY DATA FUSION ALGORITHMS ARE NOT CAPABLE OF HANDLING MULTIPLE SOURCES AND RECEIVERS COUPLED WITH MULTIPLE TRANSMISSION PATHS AND FALSE ALARMS. WE PROPOSE TO COMBINE THE LIKELIHOOD RATIO TRACKER (LRT) WITH MATCHED MODE PROCESSING TO DEVELOP A SHALLOW WATER DATA FUSION SYSTEM. LRT IS A DISCRETE, RECURSIVE, NON-LINEAR FILTER THAT COMPUTES ESTIMATES OF TARGET STATE (POSITION, VELOCITY, DEPTH) IN TERMS OFPROBABILITY DISTRIBUTIONS. LRT HAS DEMONSTRATED ITS ABILITY TO PROCESS NON-LINEAR MEASUREMENT DATA WITH NON-GAUSSIAN MEASUREMENT ERRORS IN SITUATIONS INVOLVING ACTIVE SENSORS, MULTIPLE RECEIVERS, MULTIPLE TRANSMISSION PATHS, MANEUVERING TARGETS, AND FALSE TARGETS. MATCHED MODE PROCESSING IS A NEW TECHNIQUE THAT PRODUCES TARGET RANGE AND DEPTH ESTIMATES FROM SIGNALS RECEIVED AT VERTICAL ARRAYS EVEN IN THE PRESENCE OF MULTIPLE TRANSMISSION PATHS. MATCHED MODE PROCESSING IS ROBUST TO MIS-ESTIMATION OF TRANSMISSION LOSSES RESULTING FROM SURFACE REFLECTIONS AND BOTTOM BOUNCES.