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

## 5pSA9. A study of the effective properties of complex scatterers using
multiresolution decomposition.

**B. Z. Steinberg
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*Univ. of Tel Aviv, Tel Aviv 69978, Israel
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**J. J. McCoy
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*Catholic Univ. of America, Washington, DC 20064
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Complexity in the context of radiation and scattering of waves can be
intuitively perceived as the analytical and computational difficulties
encountered when a radiating system interacts with a medium or a scatterer that
are described on a wide range of length scales. The wavelength (lambda)
constitutes a physically motivated discriminator of the various length scales
pertaining to a time harmonic scattering problem. It is convenient to refer to
the length scales of the order of (lambda) and above as the macroscales, and to
the length scales much smaller than (lambda) as the microscales. A complexity
frequently encountered in scattering problems is the one characterized by a
microscale heterogeneity that occupies domains in space measured on the
macroscale. A new formulation, tuned to govern the macroscale response
component, has been presented in several recent papers. This formulation is
sufficient for estimating the radiation of a sound field into the far-field of
a surrounding fluid. In this presentation we concentrate on the formulation's
implications. The questions addressed are: What type of microscale
heterogeneity has no footprint in macroscale response measures? What classes of
microscale heterogeneity have an identical footprint in macroscale response
measures?