Robust time reversal focusing in the ocean

Recent time-reversal experiments with high-frequency transmissions (3.5 kHz) show that stable focusing is severely limited by the time-dependent ocean environments. The vertical focal structure displays dynamic variations associated with focal splitting and remerging resulting in large changes in fo...

Full description

Saved in:
Bibliographic Details
Published inThe Journal of the Acoustical Society of America Vol. 114; no. 1; p. 145
Main Authors Kim, Seongil, Kuperman, W A, Hodgkiss, W S, Song, H C, Edelmann, G F, Akal, T
Format Journal Article
LanguageEnglish
Published United States 01.07.2003
Online AccessGet more information

Cover

More Information
Summary:Recent time-reversal experiments with high-frequency transmissions (3.5 kHz) show that stable focusing is severely limited by the time-dependent ocean environments. The vertical focal structure displays dynamic variations associated with focal splitting and remerging resulting in large changes in focal intensity. Numerical simulations verify that the intensity variation is linked to the focal shift induced by phase changes in acoustic waves resulting from sound speed fluctuations due to internal waves. A relationship between focal range shift, frequency shift, or channel depth changes is illustrated using waveguide-invariant theory. Based on the analysis of experimental data and numerical simulations, methods for robust time-reversal focusing are developed to extend the period of stable focusing.
ISSN:0001-4966
DOI:10.1121/1.1582450