Spotlight-mode SAR imaging of a three-dimensional scene using spectral estimation techniques

The authors consider the problem of synthetic aperture radar (SAR) imaging of 3D targets, given a limited amount of measured data. They explore an image reconstruction method proposed by Webb and Munson. This approach employs interpolation and a series of 2D inverse FFTs to cast the 3D imaging problem into the form of a high-resolution spectral estimation problem. The series of 1D spectral estimation problems can be solved using a variety of methods. The authors apply two of those methods: ESPRIT and RELAX to simulated 3D data for a maximum of 2 and 4 elevations. They also compare the performance of the image reconstruction algorithms with the Cramer-Rao lower bound.