Optoelectronic System For Distortion-Invariant ATR

PHYSICAL OPTICS CORPORATION (POC) PROPOSES THE DEVELOPMENT OF A ROTATION-, SCALE-, AND SHIFT-INVARIANT AUTOMATIC TARGET RECOGNITION (ATR) SYSTEM. THE SYSTEM WILL CONTAIN THREE SUBSYSTEMS: AN ELECTRONIC PREPROCESSOR FOR DATA ENHANCEMENT AND COMPRESSION; A DISTORTION-INVARIANT OPTICAL FEATURE FOR SCALE-, SHIFT-, AND ROTATION-INVARIANT TARGET REPRESENTATION; AND AN ARTIFICIAL NEURAL NETWORK FOR FINAL TARGET CLASSIFICATION. THE ELECTRONIC PREPROCESSOR WILL USE NONLINEAR PROCESSING OPERATIONS SUCH AS PYRAMIDAL AND MORPHOLLOGICAL FILTERING. THE OPTICAL DISTORTION-INVARIANT FEATURE EXTRACTOR IS BASED ON A PHASE-CODING SCHEME FOR FAST PROCESSING. AT THE END OF THE PHASE I PROJECT, A COMPLETE DESIGN OF THE PROPOSED SYSTEM OF THE OPTICAL FEATURE EXTRACTOR WILL BE DELIVERED. THE PROPOSED SYSTEM WILL BE HIGHLY RUGGED, PORTABLE, AND ROBUST, CAPABLE OF PERFORMING REAL-TIME ATR OPERATIONS FOR LOW SIGNAL-TO-NOISE RATION IMAGES. 498 OPTICS USED IN SENSORS OR MISSILE SYSTEMS ARE MADE FROM SAPPHIRE, OR SILICON CARBIDE BECAUSE OF THEIR EXCELLENT OPTICAL OR INSULATING PROPERTIES, THEIR INERT, AND THEIR ABILITY TO RESIST HARSH ENVIRONMENTS. POLISHING SAPPHIRE BY MECHANICAL OR MECHANOCHEMICAL METHODS INDUCES RESIDUAL DAMAGE AND LIMITS THE OVERALL SURFACE ROUGHNESS (USUALLY AROUND 1 MICROINCH). THIS ROUGHNESS PRODUCES SCATTERING CENTERS THAT AFFECT THE PERFORMANCE OF THE OPTICS. FURTHER, POLISHING OF LARGE AREAS AND CONTOURED SURFACES USING MECHANICAL OR MECHANOCHEMICAL METHODS IS BOTH TIME CONSUMING AND EXPENSIVE. THUS, A HIGH SPEED MODERATE COST TECHNIQUE THAT CAN POLISH OPTICAL MATERIALS WITH MINIMUM DAMAGE IS DESIRED. A NOVEL, LOW COST LASER POLISHING METHOD IS PROPOSED IN THIS PHASE I THAT WILL PRODUCE ULTRASMOOTH SAPPHIRE SURFACES. THIS TECHNIQUE HAS THE CAPABILITY TO BE ADAPTED FOR CONTOURED SURFACES AND CAN ALSO BE USED IN COMBINATION WITH INTELLIGENT MANUFACTURING SYSTEMS. THE PHASE I EFFORT WILL ESTABLISH THE FEASIBILITY OF POLISHING SAPPHIRE SUBSTRATES USING A UNIQUE LASER METHOD. THE FOLLOW ON PHASE II WILL BE DEVOTED TO POLISHING LARGE COMPLEX GEOMETRIES THAT CAN BE CHARACTERIZED AND FIELD TESTED IN SEVERAL OPTICAL APPLICATIONS.