Fast Imaging of Crack Defects in Pipes Using Fourier-Domain Migration

Plane-wave imaging (PWI) techniques have been shown to be highly effective in ultrasonic nondestructive testing (NDT) applications. This work explores PWI of liquid-filled steel pipes using an immersed transducer array. We want to ascertain the presence of backwall surface cracks by reconstructing the pipe image from the reflection data. This is challenging because the pipe's frontwall and backwall surfaces are not flat. To achieve our objective, we propose a low-cost approximate beamforming method based on Fourier-domain migration that can be used for fast initial pipe assessment.