ASA 125th Meeting Ottawa 1993 May

5aSA13. Determination of structural impedance from scattering data.

Charles F. Gaumond

Angie Sarkissian

Earl G. Williams

Naval Res. Lab., Washington, DC 20375-5000

Timothy J. Yoder

SFA, Inc., Landover, MD 20785

Knowledge of the structural impedance is significantly important in the computation of acoustic scattering and radiation because it contains all the information about the structure that is necessary for the evaluation of the scattered or radiated field in any fluid medium. The inverse problem of determining the structural impedence from scattering measurements is treated. Based on the determination of surface field quantities from acoustical holography measurements, an algorithm is developed for the reconstruction of the structural impedence from knowledge of the scattered field for a set of incident plane-wave directions. The resolution of this reconstruction is treated. Higher resolution may be obtained with near-field measurements.