Estimate of the bottom compressional wave speed profile in the northeastern South China Sea using "Sources of Opportunity"
Lynch, James F.
Newhall, Arthur E.
Schock, Steven G.
Bartek, Louis R.
MetadataShow full item record
The inversion of a broad-band "source of opportunity" signal for bottom geoacoustic parameters in the northeastern South China Sea (SCS) is presented, which supplements the towed source and chirp sonar bottom inversions that were performed as part of the Asian Seas International Acoustics Experiment (ASIAEX). This source of opportunity was most likely a "dynamite fishing" signal, which has sufficient low-frequency content (5-500 Hz) to make it complimentary to the somewhat higher frequency J-15-3 towed source (50-260 Hz) signals and the much higher frequency (1-10 kHz) chirp signals. This low frequency content will penetrate deeper into the bottom, thus extending the other inverse results. Localization of the source is discussed, using both a horizontal array for azimuthal steering and the "water wave" part of the pulse arrival for distance estimation. A linear broad-band inverse is performed, and three new variants of the broad-band inverse, based on: 1) the Airy phase; 2) the cutoff frequency; and 3) a range-dependent medium are presented. A multilayer model of the bottom compressional wave speed is obtained, and error estimates for this model are shown, both for the range-independent approximation to the waveguide and for the range-dependent waveguide. Directions for future research are discussed.
Author Posting. © IEEE, 2004. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in IEEE Journal of Oceanic Engineering 29 (2004): 1231-1248, doi:10.1109/JOE.2004.834681.
Showing items related by title, author, creator and subject.
Interannual variability of the South China Sea throughflow inferred from wind data and an ocean data assimilation product Wang, Dong Xiao; Liu, Qinyan; Huang, Rui Xin; Du, Yan; Qu, Tangdong (American Geophysical Union, 2006-07-26)The Luzon Strait transport, as an index for the South China Sea throughflow, has attracted much attention. In this study the interannual variability of the Luzon Strait transport is examined, using the Island Rule and ...
Duda, Timothy F.; Rainville, Luc (American Geophysical Union, 2008-03-25)Barotropic (surface) and baroclinic (internal) tides were measured at four mooring sites during a field investigation of acoustic propagation characteristics and physical oceanography in the northern South China Sea. The ...
Chiu, Ching-Sang; Ramp, Steven R.; Miller, Christopher W.; Lynch, James F.; Duda, Timothy F.; Tang, Tswen Yung (IEEE, 2004-10)Between late April and May 23, 2001, a suite of acoustic and oceanographic sensors was deployed by a team of U.S., Taiwan, and Singapore scientists in the northeastern South China Sea to study the effects of ocean variability ...