### ASA 127th Meeting M.I.T. 1994 June 6-10

## 5pUW13. Forward and inverse scattering from rough surfaces at low grazing
incidence.

**Mark Spivack
**

**
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*Dept. of Appl. Math. & Theor. Phys., Univ. of Cambridge, Cambridge CB3
9EW, UK
*

*
*
In acoustic wave scattering from rough surfaces at low grazing angles the
usual approximations are known to break down. In the forward-scattering regime
this case is often treated by the parabolic integral equation method. The
scattering of plane waves within this formulation is considered, and effective
reflection coefficients are derived for slightly rough surfaces. Of the
higher-order statistics, the dependence of the diffuse and specular components
upon incident angle is also examined. The problem of surface reconstruction can
be expressed in terms of coupled integral equations; it is explained how in the
parabolic case these are easily treated. A major problem, however, is
backscatter; a nonparabolic approach to this problem for low-grazing angles is
described. [Work supported by Smith Institute Research Fellowship.]