An Implementation of Synthetic Aperture Focusing Technique in Frequency Domain
2007 (English)In: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, ISSN 0885-3010, E-ISSN 1525-8955, Vol. 54, no 7, 1399-1408 p.Article in journal (Refereed) Published
A new implementation of a synthetic aperture focusing technique (SAFT) based on concepts used in synthetic aperture radar and sonar is presented in the paper. The algorithm, based on the convolution model of the imaging system developed in frequency domain, accounts for the beam pattern of the finite-sized transducer used in the synthetic aperture. The 2D fast Fourier transform (FFT) is used for the calculation of a 2D spectrum of the ultrasonic data. The spectrum is then interpolated to convert the polar coordinate system used for the acquisition of ultrasonic signals to the rectangular coordinates used for the presentation of imaging results. After compensating the transducer lobe amplitude profile using a Wiener filter, the transformed spectrum is subjected to the 2D inverse Fourier transform to get the time-domain image again. The algorithm is computationally attractive due to the use of 2D FFT. The performance of the proposed frequency-domain algorithm and the classical time-domain SAFT are compared in the paper using simulated and real ultrasonic data.
Place, publisher, year, edition, pages
2007. Vol. 54, no 7, 1399-1408 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-13380DOI: 10.1109/TUFFC.2007.400ISI: 000247578700014OAI: oai:DiVA.org:uu-13380DiVA: diva2:41150