ASA 127th Meeting M.I.T. 1994 June 6-10

5pUW4. Combined volume and surface scattering in a channel using a modal formulation.

Mark J. Beran

Shimshon Frankenthal

Dept. of Elec. Eng., Catholic Univ. of America, Washington, DC 20064

In previous work a modal approach was used to study random volume scattering in a shallow channel [M. J. Beran and S. Frankenthal, J. Acoust. Soc. Am. 91, 3203--3211 (1992)]. Here it will be shown how the effects of a rough channel surface may be included in the formulation. The propagation is studied in terms of the ensemble-averaged two-point coherence function. The two-point coherence function is expressed as the sum over both self-modal and cross-modal coherence functions. The difference between the self-modal coherence functions and the cross-modal coherence functions is discussed. Conditions are given when the cross-modal coherence functions may be neglected. A simple example will be discussed. [sup a)]Permanent address: Faculty of Engineering, Tel Aviv Univ., Ramat Aviv, Israel.