Signal Processing and Geoacoustic Inversion in Shallow Water
Abstract
The ONR is currently funding an important Seabed Characterization Experiment (SBCEX) effort. A first experiment took place on the Ne w England Mud patch (NEMP) in March 2017. A second experiment is currently (May 2021) taking place on the New England Shelf Break (N ESB), and another experiment is planned on the NEMP in 2022. In this context, the project proposes method development and data analy sis for low-frequency (0-500 Hz) acoustic propagation in relatively shallow water (from shelf to shelf break). Under these condition s, the acoustic field is interpreted as the sum of several modal components, with each mode propagating dispersively through an ocea n waveguide. The project thus focuses on modal estimation and the use of modes to perform environmental estimation, with focal point on seafloor geoacoustic inversion. The main objectives of the project are 1) developing new signal processing methods to estimate p roperties of acoustic normal modes using a single sensor (hydrophone or vector sensor); 2) developing new environmental characteriza tion methods for low-frequency acoustics in a dynamic shallow water environment, and assessing the environmental estimation performa nces; and 3) estimating geoacoustic models of the seafloor for the SBCEX areas (NEMP and NESB). More specifically, new signal proces sing methods will be developed to estimate the modal Airy phase and modal polarization (task 1). Those quantities will then be used as input for geoacoustic inversion (task 2). Further, new inversion methods, adapted to data collected on distributed arrays and/or heterogeneous data will be developed (task 3). The performance of the inversion methods proposed in this project, as well as other m ethods from the SBCEX group, will be assessed through an experimental benchmark exercise (task 4). Last but not least, an experiment al contribution to SBCEX22 is proposed: deployment of a sparse distributed acoustic array on the NEMP (task 5). All the methods dev eloped in this project will be applied on SBCEX experimental data. Approved for public release.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 22, 2021
- Source ID
- N000142112695
Entities
People
- Julien Bonnel
Organizations
- Office of Naval Research
- United States Navy
- Woods Hole Oceanographic Institution