Backscattering enhancement from rough surfaces
Abstract
Several classical theoretical developments are available to treat rough surface scattering, each with a limited parameter domain of validity. Recent experimental work uses manufactured surfaces whose parameters (height and slope) are outside these domains. Predictions include an enhancement of the scattering in the backscatter directions for random surfaces of large rms height and slope. New methods to treat these problems have been obtained. Results include further development of the mixed spectral and coordinate method for both scalar and electromagnetic problems. For the scalar case we have used this method to generate algorithms which are used to reconstruct rough surfaces from scattered field data. Two versions of the reconstruction are possible. The first is valid for small roughness and is FFT based. It reconstructs the profile using fixed frequency and fixed illumination angle data for the Dirichlet boundary condition. The second is valid in the domain of the Kirchoff approximation and is FFT based, but here on a prescribed data set involving both incident and scattered angles. For larger roughness surfaces we have observed enhancement effects using a different numerical approach.
- Publication:
-
Final Report
- Pub Date:
- March 1991
- Bibcode:
- 1991csm..reptR....D
- Keywords:
-
- Backscattering;
- Boundary Conditions;
- Electromagnetic Properties;
- Fast Fourier Transformations;
- Numerical Analysis;
- Surface Roughness;
- Surface Roughness Effects;
- Algorithms;
- Data Bases;
- Dirichlet Problem;
- Electromagnetic Spectra;
- Frequencies;
- Kirchhoff Law Of Radiation;
- Scalars;
- Communications and Radar