Improving the focal quality of the time reversal acoustic noncontact source using a deconvolution operation

Abstract

The time reversal acoustic noncontact source (TRANS) utilizes time reversal (TR) from several transducers arranged in a cavity to focus energy onto a solid surface to allow inspection of that surface. The advantage of TRANS is that multiple transducers may be used to increase the amplitude of the focused energy onto the surface and potentially allow interrogation of nonlinear surficial features such as cracks and delaminations. TR is known to be a matched signal process and therefore is limited in the temporal fidelity and spatial compression of the focused energy. Fortunately, using a deconvolution operation in conjunction with TR (or inverse filter similar to Tanter et al. [JASA, 108, 223-234 (2000)]) can greatly improve the quality of the spatial focusing as well as increasing the temporal fidelity. Visualizations of the impact of the deconvolution operation will be presented to provide insight into the increased quality of the spatial focusing along with results from using the deconvolution operation in conjunction with TRANS. © 2013 Acoustical Society of America.