Three-dimensional SAR from curvilinear apertures

Three-dimensional information content in radar data taken from suitably curved aperture paths is sufficient to allow useful 3D images to be produced by appropriate imaging techniques. The coherent CLEAN algorithm, the IMP algorithm, and maximum likelihood estimation have been used to produce 3D images from data obtained for two such scenarios. The IMP algorithm in conjunction with likelihood extremization produces images free of sidelobe leakage effects found in the CLEAN algorithm. The CLEAN and IMP algorithms find use initiating likelihood extremization on or near its global maximum. Dynamic range of such images appears dependent upon levels at which artifacts appear although valid scatterers are indicated below such levels. Artifacts appear to be a function of the image sidelobes determined by the aperture configuration. Reduction of this problem and methods to increase image size will extend the general usefulness of this technique.