Distributed acoustic sensing for 2D and 3D acoustic source localization.

Distributed acoustic sensing (DAS) technology based on Rayleigh backscattering is experiencing a rapid development and leading itself into wider applications because of the unique capability of measuring sound and vibrations at all points along the sensing fiber. However, most implementations of DAS provide the position of detected sources as a function of distance within the one-dimensional axial space along the sensing fiber. A DAS system with the capability of two-dimensional (2D) and three-dimensional (3D) acoustic source localization in air is demonstrated that uses array signal processing to deal with the spatial correlation of the information measured by optical fiber. Preliminary work has demonstrated 2D acoustic source localization for multi-targets with a narrowband signal source of the same frequency and 3D position for a moving narrowband acoustic source. The results establish a new method which opens up new areas of applications of DAS such as location and identification for static, dynamic, and multiple targets in air or water.