Analytical comparison of sensor signal processing enhancements for NDT synthetic aperture ultrasonic imaging
- 1 January 1993
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Image Processing
- Vol. 2 (1), 60-67
- https://doi.org/10.1109/83.210866
Abstract
The results of a detailed analytical study of the effects of sensor processing techniques on clutter suppression and image enhancement for nondestructive testing (NDT) systems are presented. A relatively simple beamforming/diffraction model is developed for near-field, wideband, synthetic aperture ultrasonic imaging in NDT systems. The physical model is used to quantitatively evaluate a variety of front-end sensor signal processing tradeoffs for the enhanced detection and sizing of defects. It is shown using statistical microscopic scattering calculations that a combination of increased spatial sampling and rectangular windowing can increase the signal-to-clutter ratio by ~10 dB while maintaining crack size resolutions well below future projected specifications. The sensor signal processing image enhancements are demonstrated by the construction of simulated strip-map SAFT (synthetic aperture focusing technique) images of metallic crack defects in the presence of large numbers of randomly distributed clutter (simulated grain boundary) scatterersKeywords
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