UACE2017 Proceedings: Determining the acoustical properties of an object by placing it in a random noise field

Session:
Target Echo Strength-Measurements and Modelling
Paper:
Determining the acoustical properties of an object by placing it in a random noise field
Author(s):
W. A. Kuperman, Sandrine T. Rakotonarivo, Philippe Roux, Jit Sarkar, Jeffery D. Tippmann, Zachary J. Waters, Earl G. Williams
Abstract:
The acoustical properties of an object are determined by its structural admittance Ys, also called the structural Green’s function. We develop the theory for determining Ys from measurements made when the object is placed in a random noise field and then demonstrate the procedure by Monte Carlo simulation. Next, we show the results of an experiment for a thick spherical shell that was outfitted with eight collocated microphones and accelerometers. Symmetry based interpolation was used to construct a dense surface grid of data. The structural admittance determined from the data showed excellent agreement with theory. This measurement procedure combined with the earlier formalism of Bobrovnitskii [Acoustical Physics, 52(5), 513-517, 2006] results in an extremely efficient method for determining the scattering properties of an object arbitrarily oriented in a complex, external medium. Finally we discuss future measurement methodology.
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