基于符号相干因子加权的双层介质频域相干复合平面波成像  

Fourier-domain coherent plane wave compounding imaging for two-layered medium based on sign coherence factor

作　　者：龙盛蓉[1] 陈尧[1] 孔庆茹 黄景兴 Long Shengrong;Chen Yao;Kong Qingru;Huang Jingxing(Key Laboratory of Non-destructive Testing Technology,Nanchang Hangkong University,Nanchang 330063,China;Changhe Aircraft Industries Group Co.,Ltd.,Physical and Chemical Metrology Center,Jingdezhen 333002,China)

机构地区：[1]南昌航空大学无损检测技术教育部重点实验室,南昌330063 [2]昌河飞机工业(集团)有限责任公司理化计量中心,景德镇333002

出　　处：《仪器仪表学报》2022年第3期32-39,共8页Chinese Journal of Scientific Instrument

基　　金：江西省图像处理与模式识别重点实验室开放基金(ET202008414);国家自然科学基金(62161028,51705232)项目资助。

摘　　要：为同时提高双层介质下超声相干复合平面波(CPWC)成像的质量和效率,提出一种频域波束形成与符号相干因子加权(SCF)相结合的算法。提取平面波数据的相位符号,通过修正后的频域波束形成算法对其进行波场外推。利用外推后的相位符号构建SCF加权因子对波束形成后的平面波图像进行自适应加权。结果表明,经过SCF加权,时域和频域波束形成后图像中缺陷的平均半峰值宽度基本相同,分别为时域DAS的78%和75%,频域图像的信噪比高于时域5 dB左右,在提供相同分辨率和信噪比的前提下,相比于时域波束形成下的SCF加权算法,本文所提的复合算法成像效率提升4倍以上,同时兼顾较高的成像质量和较低的运算复杂度,进而形成一种适用于双层介质无损检测的高质量、低复杂度的超声相控阵成像技术。To improve the quality and efficiency of coherent plane wave compounding(CPWC) imaging for two-layered medium, a frequency-domain beamforming algorithm combined with sign coherence factor(SCF) is proposed. The phase symbol of plane wave data is extracted. And the wave field is extracted by the modified frequency-domain beamforming algorithm. The SCF weighting factor is established by using the field extrapolated phase symbol to weight the plane wave image after beamforming. Results show that, after SCF weighting, the average full-width at half maximum of defects in the time-domain and frequency-domain beamforming images are basically identical, which are 75% and 78% of the time-domain DAS respectively. The signal-to-noise ratio of the frequency-domain images is about 5 dB higher than that of the time-domain DAS. On the premise of the same resolution and signal-to-noise ratio, the imaging efficiency of the SCF weighting algorithm for frequency-domain beamforming are more than 4 times compared to the SCF weighting algorithm for time-domain beamforming. Meanwhile, the high image quality and the low computation complexity are both considered. The proposed ultrasound phased array imaging method is suitable for double medium in nondestructive detection.

关 键 词：相干复合平面波 符号相干因子 双层介质 频域 超声 

分 类 号：TG115.28[金属学及工艺—物理冶金] TH878[金属学及工艺—金属学]