Observed limiting cases of horizontal field coherence and array performance in a time-varying internal wavefield
Collis, Jon M.
Duda, Timothy F.
Lynch, James F.
DeFerrari, Harry A.
MetadataShow full item record
KeywordAcoustic arrays; Acoustic signal processing; Acoustic wave velocity; Ocean waves; Underwater acoustic propagation
Using a moored source and horizontal/vertical line array combination, horizontal coherence properties of high signal to noise ratio (>=20 dB) 100–1600 Hz signals have been measured. Internal waves in the area of the measurement created moving episodic sound-speed anomaly structures, influencing coherence length. Measured horizontal coherence scales for 100 Hz ranged from 5 to 20 acoustic wavelengths, and were inversely related to the sound-speed anomaly strength. Horizontal field properties were compared with fields computed using modal decompositions of the vertical signals. The comparison allows azimuthal field coherence properties to be studied apart from normal-mode interference effects.
Author Posting. © Acoustical Society of America, 2008. 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 124 (2008): EL97-EL103, doi:10.1121/1.2947630.
Showing items related by title, author, creator and subject.
Modeling acoustic propagation of airgun array pulses recorded on tagged sperm whales (Physeter macrocephalus) DeRuiter, Stacy L.; Tyack, Peter L.; Lin, Ying-Tsong; Newhall, Arthur E.; Lynch, James F.; Miller, Patrick J. O. (Acoustical Society of America, 2006-12)In 2002 and 2003, tagged sperm whales (Physeter macrocephalus) were experimentally exposed to airgun pulses in the Gulf of Mexico, with the tags providing acoustic recordings at measured ranges and depths. Ray trace and ...
Piecewise coherent mode processing of acoustic data recorded on two horizontally separated vertical line arrays Udovydchenkov, Ilya A.; Brown, Michael G.; Duda, Timothy F. (Acoustical Society of America, 2012-05-25)Motivated by measurements made in the 2004 Long-Range Ocean Acoustic Propagation Experiment (LOAPEX), the problem of mode processing transient acoustic signals collected on two nearby vertical line arrays is considered. ...
Njeru, James Murwanthanje (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1992-02)An average sound speed profile over a 1000 km section of the northeast Pacific ocean is obtained using Ocean Acoustic Tomography, from data acquired during the 1987 SVLA experiment on a long (900 m) 120 hydrophone vertical ...