Prediction of a body’s structural impedance and scattering properties using correlation of random noise
Résumé
The structural or surface impedance matrix (or equivalently the inverse of the structural Green’s function) for an elastic body can be obtained by placing it in an encompassing and spatially random noise field and cross-correlating pressure and normal velocity measurements taken on its surface. The derived theory shows that the correlation method produces the exact analytic form of the structural impedance matrix. A numerical experiment is presented determining the structural impedance matrix of an infinite cylindrical shell excited by a spatially random noise field. These results are then used to compute the scattered field from a nearby point source, which is in agreement with known results. [Work supported by the Office of Naval Research.]