In this paper we investigate the use of the perfectly matched layer (PML) to truncate a time harmonic rough surface scattering problem in the direction away from the scatterer. We prove existence and uniqueness of the solution of the truncated problem as well as an error estimate depending on the thickness and composition of the layer. This global error estimate predicts a linear rate of conver...

Surface roughness has a huge impact on many important phenomena. The most important property of rough surfaces is the surface roughness power spectrum C(q). We present surface roughness power spectra of many surfaces of practical importance, obtained from the surface height profile measured using optical methods and the atomic force microscope. We show how the power spectrum determines the cont...

I have continued to work on the development of theoretical surface scattering models. My objective is to discover or devise a model that accurately predicts scattering from rough surfaces but which also can be used in practical models of acoustic propagation and scattering. In conjunction with this objective, I have been working with another ONR researcher to develop an exact numerical method f...

The LNL (linear, non-linear, linear) model has previously been successfully applied to the problem of texture segmentation. In this study we investigate the extent to which a simple LNL model can simulate human performance in a search task involving a target on a textured surface. Two different classes of surface are considered: 1/f(beta)-noise and near-regular textures. We find that in both ca...

A Rytov series approximation for rough surface scattering is presented for an analytical description of the close relation of topographic statistics and topographic scattering. The Rytov series approximation is not subject to the stringent restrictions that apply to the Born series approximation. Numerical calculations of the Rytov series approximation are conducted for several benchmark models...

We study liquid drops lying on a rough planar surface. The drops are minimizers of an energy functional that includes a random adhesion energy. We prove the existence of minimizers and the regularity of the free boundary. When the length scale of the randomly varying surface is small, we show that minimizers are close to spherical caps which are minimizers of an averaged energy functional. In p...

We review and compare two models recently developed for the impedance calculation of a rough surface. Presented at the International Computational Accelerator Physics Conference (ICAP 98) Monterey, CA September 14{18, 1998 Work supported by Department of Energy contract DE{AC03{76SF00515. WAKE OF A ROUGH BEAM WALL SURFACE K. L. F. Bane and G. V. Stupakov SLAC, 2575 Sand Hill Road, Menlo Park, C...