Echo-Doppler ultrasonic imaging with a phased array,

摘要

Abstract: This paper presents a system model and an inversion for phased array ultrasonic imaging with a moving target within a stationary background. The imaging method is based on the inversion principle that utilizes the spatial Fourier decomposition of the obtained data in the array elements. Velocity estimation can be obtained by examining the Doppler shift caused by a target moving along a scanning beam axis and Doppler spread caused by the same target moving normal to the beam. This process includes two filters in the reconstructed spatial domain and spatial frequency domain for separating a moving target's signature from the stationary background. In addition, the Doppler shift does not respond to the pulse propagation time but instead responds to the scanning time which is much slower. This slow time method makes Doppler shift and spread computable in the processing. After the velocity estimation the shifted and smeared moving target signature is able to be correctly and clearly imaged with estimated velocity vector values in the reconstructed spatial domain by a phase compensation in the spatial frequency domain. !10