NUFFT-based near-field imaging technique for far-field radar cross section calculation

Near-field images can be applied to determine the far-field radar cross section (RCS) of the target overcoming the need for long-range measurement setups. This letter presents a far-field RCS calculation technique based on the nonuniform fast Fourier transformation (NUFFT). The NUFFT is first incorporated in the near-field imaging procedure, and then is used for the subsequent RCS calculation. Comparisons of the NUFFT-based technique and the Cartesian tomography-based technique are demonstrated by means of numerical simulations as well as by measured data of objects in the outdoor range.