Radar systems and radar-cross-section (RCS) measurements were once associated only with military applications. But the expansion of radar technologies to consumer and commercial applications has created a need for lower-cost RCS measurement approaches to build practical databases of potential target information. Fortunately, work performed by M.G. Araujo, J. L. Rodriguez, J.M. Taboada, F. Obelleiro, and I. Garcia-Tunon across various universities in Spain has shown that effective radar simulations can be built from data collected from single-frequency RCS measurements.
The proposed method gathers radar-signature features of a target (an F-18 fighter aircraft was one of the two examples used as a target in the report). It creates a simulation based on a single frequency and a single direction of incidence, using any number of different electromagnetic (EM) analysis techniques. Prior to imaging, it is necessary to obtain the surface-current-density distribution of a target, typically by means of the fast multipole method (FMM) or by using a finite-difference-time-domain (FDTD) solution. The geometry of the target must be subdivided into separate cells, with the cell size chosen to provide a certain resolution of the various scatterers expected from a single-frequency signal incident on the target.
The choice of analysis method does impact the accuracy of the final results, as does the size of the cells used in the analysis. By computing the reflected signals from a target when considered as a group of different but connected geometric cells or subdomains, it is possible to create a three-dimensional reflectivity matrix for a target which can be used to create an RCS profile for that target. See "Low-Cost Procedure for Radar-Imaging Simulation," IEEE Antennas and Propagation Magazine, August 2011, p. 55.