采用分级聚焦波束形成的快速声成像算法

为了减小常规波束形成所需的庞大计算量以实现快速成像,本文提出了一种新的波束形成算法——分级聚焦波束形成。将基阵划分成各级子阵分级进行处理,对较短的子阵进行远场近似处理,逐级合并子阵进行子阵间的近场聚焦波束形成,并逐级进行波束插值。MAT- LAB仿真计算结果表明,分级聚焦法与常规波束形成相比,计算量和数据存储量大幅下降。该方法尤其适用于多焦点近场聚焦的场合。

A Fast Imaging Algorithm Using Multistage-Focusing Beamforming

In order to reduce the huge computational task of conventional delay-sum beamforming so as to implement fast imaging,this paper describes a new algorithm of beamforming——multistage-focusing beamforming.The array is divided into subarrays and multistage processing is implemented.Conventional far-field beam- forming is done for these short subarrays.At successive stages the near-field beams for pairs of subarrays are combined and additional beams are developed.The simula- tion results using MATLAB demonstrate that the multistage-focusing beamforming shows great savings in the computational load and the data storage compared with the conventional beamforming.This method is especially fit for the situation of mul- tifocus focusing in the near field.