ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

1aPA8. Sound diffraction by a ground with barriers or impedance discontinuities in a refracting atmosphere.

Y. L. Li

Wave Propagation Lab., Dept. of Elec. and Comput. Eng., Univ. of Illinois at Urbana--Champaign, 332 CSRL, 1308 W. Main Street, Urbana, IL 61801

Michael J. White

U.S. Army Construction Eng. Res. Lab., Champaign, IL 61826-9005

The exact solution for the total field is obtained for the sound diffraction due to a time-harmonic line source above a ground in a medium with linear sound-speed profile. The ground may have barriers with arbitrary shapes or impedance discontinuities parallel to the line source. The solution is in terms of an integral equation which is numerically solved by an extension of the method of moments. The effects of scattering in the region around barriers or impedance discontinuities are studied for situations for various values of the refracting strength of the sound-speed profile.