Orthogonal Matching Pursuit based Sparse Dispersive Radon Transform for Ultrasonic Guided Mode Extraction

Mode overlapping of ultrasonic guided waves challenges the signal interpretation in the field of non-destructive testing and waveguide characterization. Dispersive Radon transform (DRT), projects the array signals from distance-time domain to parameter-intercept domain (DRT domain), has been proposed for wave mode decomposition and material properties estimation. However, limited measurements along a given range of positions, so-called finite aperture problem, result in low resolution in DRT domain. In this study, considering the sparsity of guided signals in the parameter-intercept domain, orthogonal matching pursuit (OMP) is introduced to achieve a high-resolution DRT method. Simulated results prove the OMP optimized DRT can be beneficial for ultrasonic guided mode extraction and separation.