NDT Beamforming Algorithm Based on Amplitude Distribution Correlation Factor

In nondestructive testing ultrasound imaging, B-mode ultrasound line-scan focusing imaging offers the advantages of speed and concentrated energy, but its imaging quality is often compromised by clutter interference. To tackle the problem of clutter interference, this article proposes an adaptive beamforming algorithm based on instantaneous amplitude distribution correlation factor (DCF) for B-mode ultrasound line-scan focusing nondestructive testing imaging. Leveraging the differences in the distribution of instantaneous amplitudes between the background and defective regions, the DCF algorithm identifies the defective part by utilizing the inverse of the product of the range and standard deviation of the echo data. Subsequently, the background is suppressed using the calculated DCF weighting factors, and these factors are further refined by instantaneous sign coherence factor (SCF) to preserve the amplitude of the main lobe. Experimental results indicate that, compared to the delay-and-sum (DAS) algorithm, the DCF algorithm enhances the array performance index (API) and contrast ratio (CR) by 83.08% and 223.85%, respectively, in the 20# gauge steel test block, by 59.82% and 201.15%, respectively, in an aluminum test block, and by 74.52% and 120.68%, respectively, in a weld defect detection block. The DCF algorithm proposed in this article achieves a significant improvement in the quality of ultrasound imaging for nondestructive testing at the cost of a very low increase in algorithm complexity.