Inverse sound source reconstruction by exterior spherical acoustical holography with model adaptation

Alexander Mattioli Pasqual (1) , Vincent Martin (1)

1 DALEMBERT - Institut Jean Le Rond d'Alembert

Spherical acoustical holography (SAH) can be used to reconstruct the 3D sound field from acoustic data on a spherical surface, called the hologram sphere. In exterior SAH, the hologram sphere encloses all the sound sources and free-field conditions are assumed. Then, the acoustic variables can be reconstructed at any point exterior to the smallest sphere surrounding the sources (called the source sphere) by using a radiation model written in terms of spherical Hankel functions and spherical harmonics. This work deals with the inverse problem of reconstructing the radial particle velocity on the source sphere from the sound pressure field on the hologram sphere. This requires prior knowledge of the position of the source sphere inside the hologram sphere; as far as possible, these spheres must be made concentric to simplify the reconstruction equations. If the relative position of the hologram and source spheres is not known, an estimated position must be used. This may yield an inadequate propagator, so that the acoustic velocity field is poorly reconstructed. This contribution discusses the role of the relative position of the spheres in inverse source reconstruction. In addition, some strategies to improve the radiation model by adapting the source position from the hologram data are investigated.

Mots clés: spherical acoustical holography; position optimization; acoustic center; spherical harmonics

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

Alexander Mattioli Pasqual, Vincent Martin. Inverse sound source reconstruction by exterior spherical acoustical holography with model adaptation. The 18th International Congress on Sound and Vibration, Jul 2011, Rio de Janeiro, Brazil. p.1-8. ⟨hal-00612295⟩