Generation of ultrasonic tomography from time-domain propagation spectrum

The projection of several ultrasonic pulse velocity (UPV) measurements is one of the common procedures for the generation of ultrasonic tomographic images. However, only the time of arrival of ultrasonic waves or the first amplitude of the waveform after onset is evaluated. This paper presents a methodology for the generation of tomographic images from the analysis of the time-domain propagation spectrum. Nonlinear optimization techniques were applied with the use of heuristic algorithms, and the methodology effectiveness was demonstrated in simple UPV applications extended to the tomography generation. The approach provided reliable values and images in all numerical applications and showed the analysis of time spectrum significantly reduces the number of measurements required for the generation of a tomogram maintaining the quality of the results.