|Title||Grid-free compressive beamforming|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Xenaki A., Gerstoft P|
|Journal||Journal of the Acoustical Society of America|
|Type of Article||Article|
|Keywords||inversion; location; music; noise; performance; signals|
The direction-of-arrival (DOA) estimation problem involves the localization of a few sources from a limited number of observations on an array of sensors, thus it can be formulated as a sparse signal reconstruction problem and solved efficiently with compressive sensing (CS) to achieve high-resolution imaging. On a discrete angular grid, the CS reconstruction degrades due to basis mismatch when the DOAs do not coincide with the angular directions on the grid. To overcome this limitation, a continuous formulation of the DOA problem is employed and an optimization procedure is introduced, which promotes sparsity on a continuous optimization variable. The DOA estimation problem with infinitely many unknowns, i.e., source locations and amplitudes, is solved over a few optimization variables with semidefinite programming. The grid-free CS reconstruction provides high-resolution imaging even with non-uniform arrays, single-snapshot data and under noisy conditions as demonstrated on experimental towed array data. (c) 2015 Acoustical Society of America.