APPLICATION OF THE ANGULAR SPECTRUM APPROACH TO COMPUTE THE FAR-FIELDPRESSURE

The angular spectrum decomposition of an acoustic source can be used t o compute the radiation pressure in three dimensional radiation proble ms. Then, the aim of this paper is to demonstrate that the discrete fa r-field pressure can be computed from the two-dimensional (2D) discret e Fourier transform (DFT) of the normal velocity. In fact, using the a symptotic expression of the Rayleigh integral, it will be shown that t he analytical far-field pressure is given by the 2D Fourier transform of the normal velocity. Using the discrete form of this expression, gu idelines for selection of the sampling interval and the size of baffle in which the source is mounted will be given. The case of a rectangul ar source mounted in a rigid baffle and radiating into water will be c onsidered. (C) 1998 Elsevier Science B.V.