A sparse equivalent source method for near-field acoustic holography.
This study examines a near-field acoustic holography method consisting of a sparse formulation of the equivalent source method, based on the compressive sensing (CS) framework. The method, denoted Compressive-Equivalent Source Method (C-ESM), encourages spatially sparse solutions (based on the superposition of few waves) that are accurate when the acoustic sources are spatially localized. The importance of obtaining a non-redundant representation, i.e., a sensing matrix with low column coherence, and the inherent ill-conditioning of near-field reconstruction problems is addressed. Numerical and experimental results on a classical guitar and on a highly reactive dipole-like source are presented. C-ESM is valid beyond the conventional sampling limits, making wide-band reconstruction possible. Spatially extended sources can also be addressed with C-ESM, although in this case the obtained solution does not recover the spatial extent of the source.
Acoustic Technology, Department of Electrical Engineering, Technical University of Denmark, Building 352, Ørsteds Plads, DK-2800 Kongens Lyngby, Denmark.
Efren
E
Fernandez-Grande
Acoustic Technology, Department of Electrical Engineering, Technical University of Denmark, Building 352, Ørsteds Plads, DK-2800 Kongens Lyngby, Denmark.
Angeliki
A
Xenaki
Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, USA.
Peter
P
Gerstoft