8. Visualization Procedures
A real-time 32-element synthetic aperture acoustic imaging system has been developed. We can test new ideas for the system by using an acoustic array and carrying out image reconstruction on a computer. Contour plots of simple images are shown to illustrate the resolution (0.4 - 0.5 mm in range and transverse resolution) and sidelobe levels obtained with this synthetic-aperture technique. Rayleigh wave images of surface cracks and holes in metal samples have been obtained and a new type of monolithic edgebonded acoustic transducer array has been developed for use in Rayleigh wave imaging. A number of techniques for reducing the sidelobe levels and improving the resolution have been investigated. The results obtained with a new 32-tap digital delay line for deconvolving the pulse response of a transducer in real time are described.
Corl, Doug; Kino, Gordon S.; Behar, D; Olaisen, H.; and Titchener, P., "Digital Synthetic-Aperture Acoustic Imaging System" (1980). Proceedings of the DARPA/AFML Review of Progress in Quantitative NDE, July 1978–September 1979. 44.