Joint Time-Frequency Processing of Ultrasonic Signals
The backscattered signal information in ultrasonic testing is an effective method for characterization and detection of defects in materials. The complexity of materials like composites, mixed metals, multilayered fiber-reinforced composites and materials with complex structures used in nuclear power plants and spacecraft add new challenges towards the characterization and defect detection. Due to frequency dependent scattering and attenuation the backscattered ultrasonic signal is nonstationary in character. Therefore, joint time-frequency (t-f) representations of such signals are more revealing than the standard Fourier analysis.
KeywordsAttenuation Autocorrelation Acoustics
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