Three-Dimensional Scattering Center Extraction Based on Wide Aperture Data at a Single Elevation

Abstract

A methodology to reconstruct the 3-D scattering center model from the data with wide azimuthal aperture at a single elevation, such as those collected in turntable or circular synthetic aperture radar configurations, is proposed in this paper. The wide azimuthal aperture is divided into overlapped subapertures, and the 2-D scattering centers are extracted in each subaperture. These local scattering centers are rotated and mapped into the ground plane in the target coordinate system, where they are associated according to their location and amplitude consistency. Three-dimensional position of the scatterer is then estimated from the location variation of the 2-D points at different azimuths. The theoretical performance of the position estimator is analyzed, which reveals how the scatterers' azimuthal directivity and persistency affect the precision of the position estimates. The reconstructed model consisted of scattering centers described by their 3-D positions and scattering coefficient profiles at the specific depression angle. Examples using both point scatterers and computer-aided design models not only verify the validity of the methodology but also manifest the applicability of the reconstructed model in scattering analysis, data regeneration, and elevation extrapolation.