ASA 125th Meeting Ottawa 1993 May

2aAO12. Vertical coherence of long-range reverberation in a Pekeris shallow-water waveguide.

Ji-Xun Zhou

Xue-Zhen Zhang

School of Mech. Eng., Georgia Inst. of Technol., Atlanta, GA 30332

Ensheng Luo

Dezhao Wang

Inst. of Acoust., Academia Sinica, Beijing 100080, People's Republic of China

By using the averaged angular spectrum method for a shallow-water sound field [Zhou, Acta Acust. Sin. 5, 86--99 (1980)], an expression of vertical coherence of long-range reverberation in a Pekeris shallow-water waveguide is derived. The resulting vertical coherence coefficient depends on bottom reflection and bottom scattering at small grazing angles. In this talk, sea-going experiments and laboratory data analyses are presented. The measured vertical cross-correlation coefficient for long-range reverberation is given as a function of relevant parameters such as reverberation time, hydrophone separation, signal frequency, etc. It is found that the measurements agree with theoretical predictions very well. The results are encouraging for further research on the derivation of both small-angle bottom reflection and scattering from long-range reverberation in shallow water. [Work supported by ONR and the IAAS.]