Research Summaries

Back Portable, High-Efficiency, Wide-Band (500-1,200 Hz) Moored Sound Sources for Shallow-Water Low-Frequency Acoustic Propagation Studies

Fiscal Year 2010
Division Graduate School of Engineering & Applied Science
Department Oceanography
Investigator(s) Chiu, Ching-Sang
Sponsor Office of Naval Research (Navy)
Summary All of the past acoustic propagation experiments conducted in shelf and slope regions in non-US waters as part of the Shallow-Water Thrust of the Ocean Acoustics Program of the Office of Naval Research (ONR) have been constrained by the lack of portable sound sources that have frequency ranges covering the upper half (550-1,000 Hz) of the low frequency regime. This limitation has prevented the collection of comprehensive data for studying propagation physics in this upper-half of the band, and for quantifying the boundaries and overlaps in the entire low frequency-range-angle domain within which one or more environmental factors controls the characteristics and statistics in signal intensity and coherences. In a downward-refracting sound channel, these environmental factors include sound-speed variability, bathymetry changes, sediment heterogeneity, and fish schools. In order to fill the data and knowledge gaps, the procurement of two wide-band moored sources, spanning 500-800 Hz and 800-1,200 Hz, is proposed. The design is based on the proven sweeper technology developed by Teledyne Webb Research Company to achieve high efficiency. The dimension of each is compact, with the transducer, electronics and batteries configured in two Slocum-glider hulls mounted in parallel, making them easily transportable and deployable in non-US waters. The first deployment will be in the next multi-institutional shallow-water acoustics experiment that is targeted for the FY11-12 timeframe. Similar to other Naval Postgraduate School (NPS) sea-going acoustic equipment, these new sources will be treated as community assets. Their placement and signaling schemes will be designed in a joined effort to support various scientific objectives including graduate student theses of NPS as well as those of other institutions collaborating in the experiment.
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Publications Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal
Data Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal