Near to far field transformation of RCS using a compressive sensing method

摘要

Near field Inverse Synthetic Aperture Radar Cross Section (RCS) measurements are used in this study to obtain geometrically correct images of objects placed on a turntable. The images of the targets are processed using a method common in the compressive sensing field, Basis Pursuit Denoise. A near field model based on isotropic point scatterers is set up. The target model is naturally sparse and this ℓ1-minimization method works well to solve the inverse problem. The point scatterer solution is then used to obtain the far field RCS. The methods required for the imaging and the RCS extraction are described and evaluated. A comparison to image based near to far field methods utilizing conventional back projection is made. The main advantage of the method presented in this paper is the absence of clutter, noise and side lobes in the solution of the inverse problem. Separate features in the images containing the point scatterers can be selected and a processing step can be performed to obtain the far field RCS of the full target or selected parts of the target.