Using distributed acoustic sensing for ocean ambient sound analysis

Distributed acoustic sensing (DAS) is a technique that utilizes the back scattering in fiber optic cables to densely sample the strain rate in both space and time. This technique has been widely demonstrated as a powerful tool for seismic sensing, but the efficacy of submerged, under-sea cables for ocean acoustic sensing remains underexplored. The ocean observatories initiative (OOI) conducted a distributed acoustic sensing experiment in November of 2021, where two of the fiber optic cables continuously recorded the strain rate for four days. In this talk, the ambient sound field recorded by the OOI DAS experiment will be explored. A statistical comparison of hydrophone measurements and DAS measurements will be presented. Additionally, the possibility of using ocean ambient sound techniques, such as ambient noise interferometry will be explored and compared to hydrophone analysis. [Work supported by ONR.]