Ultrasonic Synthetic Aperture Focusing Using Unfocused Pulse-Echo Transducers

摘要

The lateral resolution of digital data from the unfocused pulse-echo transducers used in conventional ultrasonic inspections can be improved using the synthetic aperture focusing technique (SAFT). For practical applications it is important to minimise the level of sidelobes (artefacts) introduced by SAFT, without significant loss of resolution. This may be achieved by the inclusion of a suitable aperture weighting function in the SAFT algorithm, combined with a synthetic aperture size related to the width of the transducer beam-spread. The properties of the resulting optimized SAFT algorithms are quantified using experimental data from a series of artificial flaws (slots) of different sizes.