Acoustic source localization

Abstract: The boundary condition on the acoustic perturbation velocity at an impermeable surface in a flow is considered for the cases in which the surface generates a sound field by vibration or is acoustically deformed by an incident sound field. It is shown that in general the condition is not equivalent to the requirement of continuity of acoustic particle displacement in the direction normal to the unperturbed surface.

Abstract: A family of acoustic perturbation equations is derived for the simulation of flow-induced acoustic fields in time and space. The mean flow convection and refraction effects are part of the simulation of wave propagation. Using linearized acoustic perturbation equations the unbounded growth of hydrodynamic instabilities in critical mean flows is prevented completely. The perturbation equations are excited by source terms determined from a simulation of the compressible or the incompressible flow problem. Since the simulation of wave propagation contains the convection effects the computational domain of the flow simulation has to comprise only the significant acoustic source region. The acoustic perturbation equations are validated by computing a monopole source in a sheared mean flow, the sound generated due to a spinning vortex pair, and the sound generated by a cylinder in a crossflow.

Abstract: A method is presented for localizing acoustic sources using an array of sensors, the output of each being a vector consisting of the acoustic pressure and acoustic particle velocity. The authors derive a compact expression for the Cramer-Rao bound (CRB) on the estimation errors of the source direction-of-arrival (DOA) parameters in the multi-source multi-vector-sensor model. An explicit expression is found for the mean-square angular error (MSAE) bound for source localization with a single vector sensor. The authors present two simple algorithms for estimating the source DOA with this sensor, along with their statistical performance analyses. >

Abstract: A Little Dynamics- Survey of Wave Types and Characteristics- Damping- Impedance and Mobility- Attenuation of Structure-Borne Sound- Sound Radiation from Structures- Generation and Measurement of Structure-Borne Sound

Abstract: Problems associated with the use of intersecting hyperboloids for passive source localization from time-of-arrival difference signals are discussed. A closed-form solution for source location is presented given time-of-arrival difference measurements when the distance from the source to any arbitrary reference is unknown.