ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

4pUW14. Average acoustic field in shallow water II: Reverberation and its inverse problem.

Ji-Xun Zhou

Xue-Zhen Zhang

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

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

Average reverberation intensity and the vertical correlation coefficient for reverberation, obtained from Pekeris shallow water, are offered as possible simple test cases for numerical modeling of reverberation and bottom scattering mechanism analysis. Measurements were conducted at three different areas in the Yellow Sea and the East China Sea with water depths of 40, 29, and 52 m. These three locations have very different seabed sediments, with mean grain diameters of 0.35, 0.07, and 0.02 mm, and porosities of 35.5%, 46.2%, and 56.1%, respectively. Wideband explosive sources with 1000-g TNT charges were used to get 1/3-octave reverberation data with center frequencies ranging from 200 to 5000 Hz. Using theoretical results obtained from the angular spectrum method, both small-angle bottom reflectivity and scattering strength are derived from high reverberation-noise ratio data, including reverberation intensity and vertical coherence in shallow water. [Work supported by ONR and IAAS.]