Modulation of scattering cross sections for arbitrarily oriented composite rough surfaces - Full wave approach

As a synthetic-aperture radar scans different portions of a rough surface, the direction of the unit vector normal to the mean surface of the effective illuminated area (resolution cell) fluctuates. In this paper the modulations of the scattering cross sections of the resolution cell are determined as the normal to it tilts in planes that are in and perpendicular to the fixed reference plane of incidence. Using the full-wave approach, the scattering cross sections are expressed as a weighted sum of two cross sections. The first cross section is associated with scales of roughness within the resolution cell that are large compared to the radar wavelength, and the second cross section is associated with small-scale spectral components within the resolution cell. Thus, both specular point scattering and Bragg scattering are accounted for in a self-consistent manner. The results are compared with earlier solutions based on first-order Bragg-scattering theory.