title: Beamforming with a volumetric array of massless laser spark sources--Application in reflection tracking.
abstract: A volumetric array of laser-induced air breakdown sparks is used to produce a directional and steerable acoustic source. The laser breakdown array element is broadband, point-like, and massless. It produces an impulse-like waveform in midair, thus generating accurate spatio-temporal information for acoustic beamforming. A laser-spark scanning setup and the concept of a massless steerable source are presented and evaluated with a cubic array by using an off-line far field delay-and-sum beamforming method. This virtual acoustic array with minimal source influence can, for instance, produce narrow transmission beams to obtain localized and directional impulse response information by reflection tracking.
authors.affiliation: Department of Physics, University of Helsinki, P.O. Box 64, Helsinki FI-00014, Finland joona.eskelinen@helsinki.fi, edward.haeggstrom@helsinki.fi.
authors.forename: Joona
authors.initials: J
authors.lastname: Eskelinen
authors.affiliation: Department of Physics, University of Helsinki, P.O. Box 64, Helsinki FI-00014, Finland joona.eskelinen@helsinki.fi, edward.haeggstrom@helsinki.fi.
authors.forename: Edward
authors.initials: E
authors.lastname: Hæggström
authors.affiliation: Department of Signal Processing and Acoustics, Aalto University, P.O. Box 13000, Espoo FI-00076, Finland symeon.delikaris-manias@aalto.fi, javier.gomez.bolanos@aalto.fi, ville.pulkki@aalto.fi.
authors.forename: Symeon
authors.initials: S
authors.lastname: Delikaris-Manias
authors.affiliation: Department of Signal Processing and Acoustics, Aalto University, P.O. Box 13000, Espoo FI-00076, Finland symeon.delikaris-manias@aalto.fi, javier.gomez.bolanos@aalto.fi, ville.pulkki@aalto.fi.
authors.forename: Javier Gómez
authors.initials: JG
authors.lastname: Bolaños
authors.affiliation: Department of Signal Processing and Acoustics, Aalto University, P.O. Box 13000, Espoo FI-00076, Finland symeon.delikaris-manias@aalto.fi, javier.gomez.bolanos@aalto.fi, ville.pulkki@aalto.fi.
authors.forename: Ville
authors.initials: V
authors.lastname: Pulkki