De-Noising method to ultrasonic inspection signal of Coarse-Grained materials on wavelet transform

The application of wavelet transform to ultrasonic inspection of coarse-grained materials is discussed in this paper.To restrain the adverse effect of the scattering from coarse-grain,an algorithm using wavelet coefficient threshold pruning and reconstruction is provided to enhance SNR based on the discussion of the frequency spectrum distribution of the defect signals and grained noise.The experimental results show that the new method is more effective,and the defect is detected more easily.