CLUTTER REJECTION SIGNAL PROCESSING

THE USS STARK AND HMS SHEIFIELD PROVIDE GRAPHIC DEMONSTRATIONS OF CURRENT ANTISHIP MISSILE EFFECTIVENESS. PROVIDING PASSIVE LOW FALSE ALARM RATE DETECTION AND TRACK OF MISSILE TARGETS FOR US NAVAL SURFACE COMBATANTS PROMISES IMPROVED ATTACK WARNING TIMES, STEALTH AND WEAPONS TARGETING. THIS EFFORT WILL INVESTIGATE A NUMBER OF PROMISING APPROACHES TO REJECTING CLUTTER IN INFRARED SEARCH AND TRACK SETS (IRSTS) TO ACHIEVE THESE GOALS. THE ALGORITHMS PROPOSED FOR INVESTIGATION FALL INTO TWO BROAD CLASSES; THE FIRST ARE NONLINEAR SPATIAL FILTERS OF THE MEDIAL TYPE. HISTORICALLY, NONLINEAR FILTERS WHEN FOUND, OFFER SUPERIOR PERFORMANCE TO LINEAR FILTERS. THE SECOND ALGORITHM CLASS FALLS UNDER THE HEADING OF VELOCITY HYPOTHESIS TESTING (VHT). THIS APPROACH REMOVES STRONGLY CORRELATED BACKGROUND CLUTTER USING A SIMPLE LOW PASS SPATIAL FILTER. THE LARGELY UNCORRELATED HIGH SPATIAL FREQUENCY BACKGROUND REMAINS. THE RESIDUAL SCENES ARE THEN SHIFTED AND AVERAGED OVER MULTIPLE FRAMES FOR ALL POSSIBLE TARGET VELOCITIES. THE AVERAGED FRAME SET OR SETS THAT ARE SHIFTED AT THE EMBEDDED TARGET VELOCITIES WILL HAVE TARGET SIGNAL ADDED CONSTRUCTIVELY AND THUS PROVIDE TARGET DETECTION. PRELIMINARY RESULTS WITH THIS APPROACH APPEAR QUITE PROMISING. IF SUCCESSFUL, SIGNIFICANT IMPROVEMENT OVER CURRENT SYSTEM PERFORMANCE IS LIKELY.