The Wavenumber-domain Algorithm in Multi-mode Imaging for Full Matrix Capture

Ultrasonic imaging with full matrix capture (FMC) data is an emerging technique applied for nondestructive testing (NDT) of various industrial components. Nevertheless, this imaging modality suffers from heavy burden of reconstruction time consumption due to the large size of FMC data. Recently, wavenumber-domain reconstruction of ultrasonic imaging like extended phase shift migration (EPSM) taking advantages of computational efficiency have been developed to replace conventional time-domain reconstruction methods, especially for light-weight real-time NDT. However, current EPSM can only support direct-mode ultrasonic imaging, and multi-mode, like half-skip and full-skip modes, ultrasonic imaging can detect cracks near bottom boundary that is insensitive to direct-mode. To this end, EPSM is extended to adapt for multi-mode ultrasonic imaging, including half-skip, full-skip and wave mode conversion cases in this paper. The performance of the proposed reconstruction method is demonstrated by experiments, and the results shows the proposed method achieves equivalent imaging quality but with up to one-sixteenth time consumption compared with conventional time-domain reconstruction.