基于MGB模型的改进合成孔径成像算法

Improvement of SAFT based on multi-Gaussian beam modeling

超声检测中,合成孔径聚焦技术(SAFT)是一种通过叠加A扫描数据得到缺陷图像的信号后处理技术,而多高斯声束(MGB)模型可以有效地计算和仿真超声声场的特性。文中采用MGB模型改进SAFT算法,得到新的成像方法称为MGB-SAFT。实验结果表明,MGB-SAFT可以有效优化缺陷图像,特别是提高位于叠加位移场的有效区域内缺陷的成像质量。

In the ultrasonic testing,synthetic aperture focusing technique（SAFT） is a signal processing technique which can produce flaw images by superposing of A-scan waveform,and multi-Gaussian beam（MGB） model can explicitly compute and simulate the ultrasonic sound field. This paper multiplied the A-scan waveform by the ultrasonic beam radiations obtained by MGB,so-called MGB-SAFT. It shows that MGB-SAFT can effectively improve the flaw image,especially when the flaw is in the effective area by superposition of displacement field.