Underwater tunable organ-pipe sound source
MetadataShow full item record
KeywordAcoustic generators; Underwater sound; Acoustic resonators; Oceanographic equipment; Seismology
A highly efficient frequency-controlled sound source based on a tunable high-Q underwater acoustic resonator is described. The required spectrum width was achieved by transmitting a linear frequency-modulated signal and simultaneously tuning the resonance frequency, keeping the sound source in resonance at the instantaneous frequency of the signal transmitted. Such sound sources have applications in ocean-acoustic tomography and deep-penetration seismic tomography. Mathematical analysis and numerical simulation show the Helmholtz resonator's ability for instant resonant frequency switching and quick adjustment of its resonant frequency to the instantaneous frequency signal. The concept of a quick frequency adjustment filter is considered. The discussion includes the simplest lumped resonant source as well as the complicated distributed system of a tunable organ pipe. A numerical model of the tunable organ pipe is shown to have a form similar to a transmission line segment. This provides a general form for the principal results, which can be applied to tunable resonators of a different physical nature. The numerical simulation shows that the “state-switched” concept also works in the high-Q tunable organ pipe, and the speed of frequency sweeping in a high-Q tunable organ pipe is analyzed. The simulation results were applied to a projector design for ocean-acoustic tomography.
Author Posting. © Acoustical Society of America, 2007. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 122 (2007): 777-785, doi:10.1121/1.2751268.
Suggested CitationJournal of the Acoustical Society of America 122 (2007): 777-785
Showing items related by title, author, creator and subject.
Observationally constrained modeling of sound in curved ocean internal waves: Examination of deep ducting and surface ducting at short range Duda, Timothy F.; Lin, Ying-Tsong; Reeder, D. Benjamin (Acoustical Society of America, 2011-09)A study of 400 Hz sound focusing and ducting effects in a packet of curved nonlinear internal waves in shallow water is presented. Sound propagation roughly along the crests of the waves is simulated with a three-dimensional ...
Low-frequency broadband sound source localization using an adaptive normal mode back-propagation approach in a shallow-water ocean Lin, Ying-Tsong; Newhall, Arthur E.; Lynch, James F. (Acoustical Society of America, 2012-02)A variety of localization methods with normal mode theory have been established for localizing low frequency (below a few hundred Hz), broadband signals in a shallow water environment. Gauss-Markov inverse theory is employed ...
Temporal and cross-range coherence of sound traveling through shallow-water nonlinear internal wave packets Duda, Timothy F. (Acoustical Society of America, 2006-06)Expressions governing coherence scales of sound passing through a moving packet of nonlinear internal waves in a continental shelf environment are presented. The expressions describe the temporal coherence scale at a point, ...