The relationship of singular value decomposition to wave-vector filtering in sound radiation problems

Singular value decomposition (SVD) has recently been suggested as a filtering tool to analyze acoustic radiation. The relationship between this filtering technique and the more familiar wave vector filtering is examined. For a geometry with a preferred axis, the source ‘‘modes’’ are found to consist approximately of a single wave number, and the accompanying radiation modes are thus beams. Some simple examples are worked out to illustrate the general behavior of the filtering, and some of the properties of the beams are given.