DISTRIBUTED ACOUSTIC SENSING

摘要

This application describes methods and apparatus for distributed acoustic sensing providing enhanced sensitivity for certain acoustic signals. The method uses a fibre optic distributed acoustic sensing (DAS) apparatus (106) to detect acoustic signals wherein the fibre optic distributed acoustic sensor comprises at least one optical fibre (104) deployed in an area of interest (204) such that at least one section of said optical fibre is deployed to monitor the acoustic response of a cavity (206) to incident acoustic signals. The cavity is dimensioned such that the cavity resonates at a desired frequency and thus the relevant sensing portions of the DAS sensor show an enhanced response to acoustic signals which excite resonance in the cavity. The optical fibre (104) may be deployed to run through said cavity.