IMAGING WITH REDUCED DATA

Abstract

Data collection requirements can be much reduced by recording only the times of arrival of echoes. Further reduction may be achieved by reducing amplitude data recorded to three or even to one bit, while still obtaining acceptable images. Simple reconstruction algorithms which include deblurring functions allow rapid image processing. Cylindrical specimens may be scanned using a standard commercial immersion transducer, since the curved surface provides the necessary beam divergence. Appropriate transducer positioning allows either compression or shear wave imaging; combining both in one image provides easier interpretation and gives sensitivity to a range of defect orientations.