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

## 5pUW13. Modeling of backscattering by bottom volumetric inhomogeneities.

**Dajun Tang
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*Dept. of Appl. Ocean Phys. & Eng., Woods Hole Oceanogr. Inst., Woods Hole,
MA 02543
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It has been recognized that when a sound wave encounters the ocean bottom,
part of the energy will be scattered by volumetric inhomogeneities in the
bottom. To simplify the mathematics, previous efforts in modeling the
volumetric scattering process invoke some forms of plane-wave approximation to
either or both of the forward and backward propagating fields. Since the ocean
bottom has different acoustic properties from that of the water column,
particularly since it often has a more complicated structure, introduction of
the plane-wave approximation casts clouds on the validity of the modeling
results. Here an approach is presented that uses the exact forward and backward
propagating fields and calculates the backscattering strength numerically in
the spatial domain. The bottom is assumed to be generally layered with
superimposed random scatterers which have given correlation functions. Finally
the validity of this model and its range of applicability will be discussed.