NEAR FIELD OCEAN ACOUSTIC IMAGING WITH A LINEAR ARRAY

THIS PROPOSAL IS ADDRESSED TO THE ASW PROBLEM OF INCREASING PROBABILITY OF DETECTION AND TARGET LOCALIZATION IN LONG RANGE SURVEILLANCE USING A PASSIVE UNDERWATER ACOUSTIC ARRAY. THE INNOVATIVE CONCEPT PROPOSED IS HIGH SPEED, HIGH RESOLUTION OCEAN ACOUSTIC IMAGING IN TWO DIMENSIONS (RANGE AND AZIMUTH). THE TECHNIQUE PROPOSEDTO ACCOMPLISH THIS IS THE USE OF A VERY LONG, FIXED, HORIZONTAL LINE ARRAY (VERY LARGE ARRAY OR VLA) FOCUSED IN THE NEAR FIELD, AND USING ORIGINAL METHODS OF HIGH SPEED NEAR FIELD DIGITAL BEAMFORMING, AND TWO DIMENSIONAL NEAR FIELD PATTERN SYNTHESIS TO ACHIEVE VERY LOW SIDE-LEVELS. THE CONCEPT HAS THE POTENTIAL OF PROVIDING A SOLUTION TO MANY OF THE PROBLEMS IN SUBMARINE DETECTION WHICH ARE DISCUSSED IN THE PROPOSAL.