The Use of Instantaneous Phase for Improving Saft Images

Abstract

In the SAFT technique (Synthetic Aperture Focusing Technique) each element operates in pulse-echo mode, requiring only on e transmit/receive channel. The generated beam pattern can present grating lobes, even if the pitc h is half wavelength, which are related to image quality. By considering the instantaneous phase of the signals detected by each transducer, it is possible to estimate if the signal used in the delay-and-sum algorithm, for each combination of array element and image pixel, is due to a reflector or if it is noise, improving the contrast and reducing the grating lobes effects.