Ranging bowhead whale calls in a shallow-water dispersive waveguide
Abstract
This paper presents the performance of three methods for estimating the range of broadband (50–500 Hz) bowhead whale calls in a nominally 55-m-deep waveguide: Conventional mode filtering (CMF), synthetic time reversal (STR), and triangulation. The first two methods use a linear vertical array to exploit dispersive propagation effects in the underwater sound channel. The triangulation technique used here, while requiring no knowledge about the propagation environment, relies on a distributed array of directional autonomous seafloor acoustics recorders (DASARs) arranged in triangular grid with 7 km spacing. This study uses simulations and acoustic data collected in 2010 from coastal waters near Kaktovik, Alaska. At that time, a 12-element vertical array, spanning the bottom 63% of the water column, was deployed alongside a distributed array of seven DASARs. The estimated call location-to-array ranges determined from CMF and STR are compared with DASAR triangulation results for 19 whale calls. The vertical-array ranging results are generally within ±10% of the DASAR results with the STR results providing slightly better agreement. The results also indicate that the vertical array can range calls over larger ranges and with greater precision than the particular distributed array discussed here, whenever the call locations are beyond the distributed array boundaries.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 01, 2014
- Source ID
- 10.1121/1.4881924
Entities
People
- Aaron M. Thode
- David R. Dowling
- Shima Abadi
- Susanna B Blackwell
Organizations
- Office of Naval Research
- University of California, San Diego
- University of Michigan