Synthetic aperture focusing ultrasound imaging technique used signal processing method to analysis ultrasonic echo data. It let the performance of transducer with small apertures be as well as the transducer with large aperture. It can still obtain high azimuth resolution image and form three-dimensional image, when it was operated at lower operating frequency. This paper describes the history and the theory of synthetic aperture focusing ultrasound imaging technology. It also contains the development of the synthetic aperture focusing ultrasound imaging technology in China and at abroad. And lots of excellent synthetic aperture focusing ultrasound imaging algorithms were listed in this paper. We analyzed the deficiencies and problems of the existing ultrasound focusing algorithms. And we made forecast about the development of synthetic aperture technology in nondestructive testing.
Low-frequency ultrasound imaging using compressed-parametric ultrasound with application of synthetic aperture focusing