Bottom Interaction in Long Range Acoustic Propagation
Abstract
Observations and theory for ocean basin-scale acoustic propagation are based on nearly two decades of work in the North Pacific Ocean utilizing controlled sources and vertical and horizontal receiver arrays. Broadband sources are considered with typical center frequencies of 250, 75, and 28 Hz. Many aspects of observed long-range acoustic fields are statistical in nature because of scattering due to ocean internal waves and density compensated fine structure. There are two distinct scattering regimes observed in the broadband multipath arrival pattern (Figure 1)[Colosi, 2004]: one in which scattering is relatively weak and clear time-resolved wavefronts are evident, and one in which a complex interference pattern is seen. Associated with both regimes is significant in-filling of acoustic energy into deterministic shadow zones, especially when the receivers are near the seabed or when the sources are off the sound channel axis. The long-term goal of this project is to understand long-range acoustic propagation in the ocean, and at the moment we do no understand the physical mechanisms responsible for the leakage of coherent energy out of the sound channel.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2006
- Accession Number
- ADA613683
Entities
People
- Ralph Stephen
Organizations
- Woods Hole Oceanographic Institution