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Signal processing in acoustic microscopy with applications to nondestructive evaluation

: Arnold, W.; Morsch, A.

World Scientific, Singapore:
Ultrasonic Signal Processing
Singapore, 1989
ISBN: 9971-50-864-8
Course on Ultrasonic Signal Processing <3, 1988, Erice>
Fraunhofer IZFP ()
acoustic holography; acoustic microscopy; akustische Holographie; akustische Mikroskopie; ceramic; defect detection; Fehlerdetektion; Keramik; signal processing; Signalverarbeitung akustischer Signale

We present our recent results to use signal processing techniques to extend the capability of Acoustic Microscopy in nondestructive evaluation. The V(z)-measurement technique for the evaluation of surface wave velocities with the Scanning Acoustic Microscope (SAM) was applied to nanocrystalline Pd-samples. Powerspectrum and cepstrum-analysis were used to derive the grain size from a SAM line-scan over a polycrystalline material. Scanning Laser Acoustic Microscope (SLAM) images which are acoustic holograms can be improved by backpropagation in the Fourier domain of the displacement field measured at the surface of the sample. We applied this technique to delineate the size of defects in advanced ceramics.