12. Techniques for Flaw Reconstruction Using Short Wavelengths
Acoustic imaging may be accomplished by a process involving the measurement of the amplitude and phase of the wavefront at a remote region and then the reconstruction, using mathematical techniques, of the fields at or near the scattering region. Since the system is coherent, both amplitude and phase images may be obtained. The current system under study employs pulsed CW tone bursts in order to reduce stray echo problems, with quadrature phase detection followed by a digital hardware processor for implementing the reconstruction algorithm. Finally, the image is processed for display and analysis.
Lakin, Ken, "Acoustic Imaging and Image Processing by Wavefront Reconstruction Techniques" (1979). Proceedings of the ARPA/AFML Review of Progress in Quantitative NDE, July 1977–June 1978. 82.