金属圆棒超声螺旋扫查检测的合成孔径成像技术
李振杰, 蔡桂喜, 张博, 李经明, 李建奎

Synthetic Aperture Imaging Technology for Ultrasonic Spiral Scanning Detection of Metal Bars
LI Zhenjie, CAI Guixi, ZHANG Bo, LI Jingming, LI Jiankui
图3 极坐标系下合成孔径弧度(SAR)推导示意图
Fig.3 Schematics about synthetic aperture radian (SAR) derivation in polar coordinate (ψ—intermediate variable used to calculate γ and γ', is the sum of half aperture angle of the virtual source and half of the SAR)
(a) for scanning at d<R side (b) for scanning at d>R side