2-D and 3-D Near-Field ISAR Imaging Techniques For the Far-Field RCS Characterization of Antennas and General Scattering Objects
T. Vaupel
The determination of the scattering properties of antennas and/or other radar targets is of growing interest for object identification and for the subsequent reduction of the radar cross section (RCS). The direct measurement of the far-field RCS typically requires long range arrangements or compact range set-ups with high-quality parabolic reflectors.
To overcome the drawbacks of these methods, we apply different kinds of near-field inverse synthetic aperture radar (ISAR) techniques to create 2-D or 3-D images of the targets which are situated on a turntable. During the imaging process, distortions due to interactions of the target with the turntable or the measurement chamber are reduced as well. These images provide an in-depth insight into the scattering mechanisms of the targets.
In addition, these images are subsequently used to extract also the far-field RCS without further costly measurement effort. The 2-D imaging techniques are mainly restricted to flat targets, whereas the recently developed 3-D techniques allow the characterization of widely arbitrary objects.