Selective focusing through target identification and experimental acoustic signature extraction: Through-aberration experiments

In the first part of this work (Rodriguez et al. 2016), the selective focusing through identification and experimental acoustic signature extraction (SelF-EASE) method was presented, and its potential for accurate ultrasound focusing was assessed via numerical experiments. In the second part of this work, the inversion procedure and focusing signal extraction are improved in terms of reliability and computation time, and experimental results are presented. First, the improved signature extraction process is evaluated with two experimental aluminum samples. Second, the improved focusing process is experimentally performed on a target immersed in water behind an unknown aberration layer. Compared with the time-of-flight methods, the measured intensity fields greatly improve in terms of accuracy without any further knowledge of the medium.