Detecting and localizing pipe changes via matched field processing.

In this work we shall demonstrate that the presence of some pipe changes, e.g., blockages can be detected via matched field processing given an array of two or more microphones. In particular, the location of such transient irregularities can also be determined using this technique. We shall show data processed with this technique for a variety of blockages in a variety of locations for a variety of pipes (concrete, PVC, and clay). There is no acoustic modeling of the fields required, and only the simple linear processor is applied. The method can be used to determine the location of change and its severity.