Index of content:
Volume 123, Issue 3, March 2008
- ACOUSTIC SIGNAL PROCESSING 
Sound field separation technique based on equivalent source method and its application in nearfield acoustic holography123(2008); http://dx.doi.org/10.1121/1.2837489View Description Hide Description
A technique for separating sound fields using two closely spaced parallel measurementsurfaces and based on equivalent source method is proposed. The method can separate wave components crossing two measurementsurfaces in opposite directions, which makes nearfield acoustic holography (NAH) applications in a field where there exist sources on the two sides of the hologram surface, in a reverberant field or in a scattered field, possible. The method is flexible in applications, simple in computation, and very easy to implement. The measurementsurfaces can be arbitrarily shaped, and they are not restricted to be regular as in the traditional field separation technique. And, because the method performs field separation calculations directly in the spatial domain—not in the wave number domain—it avoids the errors and limitations (the window effects, etc.) associated with the traditional field separation technique based on the spatial Fourier transform method. In the paper, a theoretical description is first given, and the performance of the proposed field separation technique and its application in NAH are then evaluated through experiments.