INNOVATIVE METHODS FOR SUBMARINE DETECTION

A NOVEL ACTIVE SONAR IS SUGGESTED WHEREIN THE CAVITATION NOISE OF A SHIP'S SCREWS PROVIDES INSONIFICATION OF DISTANT TARGETS AND A TOWED LINE ARRAY PASSIVE SONAR PROVIDES THE RECEIVER OF REFLECTED SIGNALS. THE UNDERWATER RADIATED NOISE SOURCE IS CONTINUOUS IN FREQUENCY AND TIME, AND IS OF MODEST POWER. AN OWNER-SHIP OR COOPERATING SHIP OR SUBMARINE TOWED LINE ARRAY WILL CONTINUOUSLY MONITOR THE SOURCE SHIP RADIATION IN A USEFUL LOW-TO-MID FREQUENCY INTERVAL. DETECTION WILL BE EFFECTED BY CROSS-CORRELATING MONITORED SOURCE SIGNALS WITH RECEIVER BEAM OUTPUT SIGNALS. THE POTENTIAL PROCESSING GAIN IS PROPORTIONAL TO TIME-BANDWIDTH PRODUCT. NUMERICAL ESTIMATES INDICATE THAT IF THE POTENTIAL PROCESSING GAIN IS REALIZED, RELIABLE DETECTION OF SUBMARINES IS POSSIBLE IN THE FIRST CONVERGENCY ZONE. THIS BY ANY TLA SHIP WITH THE NECESSARY COMPUTING POWER. IT IS PROPOSED TO INVESTIGATE FEASIBILITY BY SIZING THAT COMPUTING POWER AND BY EXAMINING SEVERAL FACTORS WHICH CAN COMPROMISE THE PROCESSING GAIN. IT IS FURTHER PROPOSED TO PLAN ANY NECESSARY MEASUREMENTS AND A DEMONSTRATION OF FEASIBILITY, IF INDICATED.