A design methodology for 2D sparse NDE arrays using an efficient implementation of refracted-ray TFM

An algorithm has been developed that allows extremely efficient calculation of the total time of flight of an acoustic ray through two layer media, taking into account the effects of refraction through a 3D non-planar surface. The approach has been implemented on GP-GPU hardware, and embedded within the Total Focussing Method (TFM) imaging algorithm. This new software module supports arbitrary location of probe elements, array element directivity, arbitrary curved interface between two media, arbitrary transmit/receive sequences and any 1D/2D/3D image size for reconstructing the ultrasonic image from raw RF ultrasonic data. This allows calculation of the Point Spread Function of the probe at a range of points in its field of view, in a practical timeframe. Methodology, performance benchmarks, and possible applications are discussed.