FEATURE ENHANCED ULTRASONIC FLAW DETECTION AND MICROSTRUCTURE CHARACTERIZATION ALGORITHMS FOR NDE SYSTEMS

IN THIS PROJECT, SOME NOVEL SIGNAL-PROCESSING TECHNIQUES FOR FEATURE-ENHANCED, ULTRASONIC NDE SYSTEMS WILL BE EXAMINED AND IMPLEMENTED. THE PROCESSING TECHNIQUES HAVE TWO OBJECTIVES: TO REDUCE THE BACKGROUND NOISE IN ORDER TO IMPROVE FLAW VISIBILITY AND SIZING, AND TO OBTAIN SIGNAL PARAMETERS THAT CAN BE CORRELATED TO THE MICROSTRUCTURE FOR CHARACTERIZATION. AN INTERACTIVE SOFTWARE PACKAGE FOR AN APPLE MAC II PLATFORM, ADAPTABLE TO THE NDE ULTRASONIC SYSTEM AT NASA, WILL BE DEVELOPED AND IMPLEMENTED. FOR ENHANCED ULTRASONIC FLAW DETECTION, A SPLIT-SPECTRUM PROCESSING FOLLOWED BY AVERAGING, MEDIAN FILTERING, MINIMUM DETECTION, QUADRATIC OPTIMAL DETECTION, AND GENERALIZED-ORDER STATISTIC FILTERING WILL BE DEVELOPED. NOVEL ALGORITHMS FOR MICROSTRUCTURE IMAGING AND CHARACTERIZATION SUCH AS TEMPORAL SMOOTHING, DISPERSIVE VELOCITY ESTIMATION, CORRELATION PROCESSING, HOMOMORPHIC PROCESSING, POWER SPECTRUM AND MOMENT ESTIMATION, AND LINEARPREDICTIVE CODING WILL BE DEVELOPED AND IMPLEMENTED. IN THIS PROJECT, SOME NOVEL SIGNAL-PROCESSING TECHNIQUES FOR FEATURE-ENHANCED, ULTRASONIC NDE SYSTEMS WILL BE EXAMINED AND IMPLEMENTED. THE PROCESSING TECHNIQUES HAVE TWO OBJECTIVES: TO REDUCE THE BACKGROUND NOISE IN ORDER TO IMPROVE FLAW VISIBILITY AND SIZING, AND TO OBTAIN SIGNAL PARAMETERS THAT CAN BE CORRELATED TO THE MICROSTRUCTURE FOR CHARACTERIZATION. AN INTERACTIVE SOFTWARE PACKAGE FOR AN APPLE MAC II PLATFORM, ADAPTABLE TO THE NDE ULTRASONIC SYSTEM AT NASA, WILL BE DEVELOPED AND IMPLEMENTED. FOR ENHANCED ULTRASONIC FLAW DETECTION, A SPLIT-SPECTRUM PROCESSING FOLLOWED BY AVERAGING, MEDIAN FILTERING, MINIMUM DETECTION, QUADRATIC OPTIMAL DETECTION, AND GENERALIZED-ORDER STATISTIC FILTERING WILL BE DEVELOPED. NOVEL ALGORITHMS FOR MICROSTRUCTURE IMAGING AND CHARACTERIZATION SUCH AS TEMPORAL SMOOTHING, DISPERSIVE VELOCITY ESTIMATION, CORRELATION PROCESSING, HOMOMORPHIC PROCESSING, POWER SPECTRUM AND MOMENT ESTIMATION, AND LINEARPREDICTIVE CODING WILL BE DEVELOPED AND IMPLEMENTED.