An improved image-based Near-Field-to-Far-Field Transformation

An improved approach to determination of radar cross section (RCS) of electrically large targets from the scattered field measured with a monostatic radar over a circle in the near-field of the targets is presented. The frequency- and azimuth-domain scattering data are used to calculate a reflectivity map (radar image) of the target, from which RCS of the target is determined. The characteristic features of the proposed version of Near-Field-to-Far-Field Transformation (NFFFT) are the use of the calibrated signal from the network analyzer as the input data in the transformation and an improved focusing operator for producing reflectivity maps. The combination of these features is expected to result in a practical and more accurate approach to the analysis of scattering properties of electrically large targets.