Relation between sampling frequency, number of elements, and truncation index in truncated singular value decomposition of probe array UT for inspecting silicon nitride

Ultrasonic Inspection is effective for inspecting ceramic materials because ultrasonic waves are easily propagated in general ceramic materials. Aperture synthesis cannot derive high quality image of internal defects in ceramic sample because the acoustic velocity of ceramic materials is very high, compared to metal samples. In this study, internal defect images were reconstructed by Truncated Singular Value Decomposition (TSVD). We investigated how the sampling frequency, number of elements, and truncation index affect the reconstructed defect images.