title: Near field acoustic holography with microphones on a rigid sphere (L).
abstract: Spherical near field acoustic holography (spherical NAH) is a technique that makes it possible to reconstruct the sound field inside and just outside a spherical surface on which the sound pressure is measured with an array of microphones. This is potentially very useful for source identification. The sphere can be acoustically transparent or it can be rigid. A rigid sphere is somewhat more practical than an open sphere. However, spherical NAH based on a rigid sphere is only valid if it can be assumed that the sphere has a negligible influence on the incident sound field, and this is not necessarily a good assumption when the sphere is very close to a radiating surface. This Letter examines the matter through simulations and experiments.
authors.affiliation: Acoustic Technology, Department of Electrical Engineering, Technical University of Denmark, Building 352, DK-2800 Kongens Lyngby, Denmark. fja@elektro.dtu.dk
authors.forename: Finn
authors.initials: F
authors.lastname: Jacobsen
authors.forename: Guillermo
authors.initials: G
authors.lastname: Moreno-Pescador
authors.forename: Efren
authors.initials: E
authors.lastname: Fernandez-Grande
authors.forename: Jørgen
authors.initials: J
authors.lastname: Hald
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D003198:Computer Simulation; D004867:Equipment Design; D006696:Holography / Q000295:instrumentation*; D008962:Models, Theoretical; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D011312:Pressure; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014160:Transducers, Pressure