Acoustic field imaging based on fiber-optic distributed acoustic sensors for subsea applications
Abstract
This project aims to enhance the capabilities of fiber-optic distributed acoustic sensors (DAS) to detect static and moving objects(e.g. acoustic sources) at far distances from a optical fiber cable used for sensing. In particular, DAS technology allows spatially-resolved monitoring of mechanical vibrations along tens of kilometers of optical fiber, with meter-scale resolving spatial resolution. This way, DAS technology coverts a single optical fiber in tens of thousands independent acoustic sensors, all simultaneously and synchronously interrogated. While DAS technology only permits the monitoring of the mechanical vibrations reaching the sensing optical fiber itself, in this project we will investigate signal processing methods for imaging of the acoustic field propagating evenat positions where no optical fiber is deployed for DAS monitoring (e.g. tens of kilometer away from the fiber cable). This innovative approach, based on acoustic beamforming, will facilitate real-time detection and spatial localization of underwater and superficial objects using even already deployed submarine optical fibers. However, integrating beamforming methods with DAS measurements poses challenges due to the uneven longitudinal response of DAS sensors, and therefore specific approaches must be investigated. The capabilities and limitations of the acoustic imaging approaches will be studied, including also the development of specific laboratorytests to investigate the impact of the fiber layout and directional response of DAS sensing technologies.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 09, 2024
- Source ID
- N629092412124
Entities
People
- Marcelo Soto
Organizations
- Federico Santa María Technical University
- Office of Naval Research
- United States Navy