Optimized algorithm for synthetic aperture imaging

In this paper we present a novel synthetic aperture imaging algorithm based on concepts used in synthetic aperture radar (SAR) and sonar (SAS). 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 Fourier transform is used for the calculation of 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. After windowing, the transformed spectrum is subjected to the 2D inverse Fourier transform to get the time domain image again. Performance of the proposed algorithm and the classical time-domain SAFT are compared in the paper using both simulated and real ultrasonic data.