The Effect of Clustered Scatterers on Volume Reverberation
Abstract
The long term goal of this work is to further the understanding of how clustering in clouds of discrete scatterers has an effect on both forward propagating and backscattered acoustic fields. Clustering is considered to be present when there are spatially dependent correlations in the fluctuating positions of the scatterers. For example, bubble clouds created by oceanic breaking waves have been observed to exhibit clustering at a level that would have a significant impact on the forward propagating acoustic field. Clustering is also expected to be present in fish aggregations (e.g., nearest neighbor distances, school morphologies driven by behavior, inter-school spacing), and consequently should be accounted for when examining bioclutter. This work is based on (a) refining theoretical approaches so that they include clustering; and (b) observing clustering in the important classes of discrete volume scatterers in the ocean. This objectives of this research are to: (1) further develop the basic constructs that have previously been used for examining clustering amongst bubbles so that it can be used to examine reverberation caused by clustering in fish aggregations at mid- to low-frequencies (i.e., at or near swim bladder resonances), and (2) leverage existing fisheries high resolution multibeam sonar data collection efforts (or other similar efforts) to look for clustering within, or between, aggregations of fish, and to then to predict the effect of this clustering on volume reverberation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2010
- Accession Number
- ADA542186
Entities
People
- Tom Weber
Organizations
- University of New Hampshire