Fast two-dimensional imaging of scattering centers using the nonuniform FFT

Radar imaging of target scattering centers can be of great diagnostic utility. Conventionally, the radar image has been produced by a technique widely used in computer-aided tomography (CAT), e.g. the filtered backprojetion (FBP) algorithm. FBP reconstruction produces high quality images by handling the measured data directly in polar format. However, the FBP algorithm is more computationally complex than the direct Fourier methods. This paper develops fast two-dimensional (2-D) imaging of scattering centers using a nonuniform fast Fourier transform (NUFFT) algorithm. The proposed method is first compared to the conventional FBP approach on simulated data and then applied to real data sets measured on the RCS test range. Results suggest that the NUFFT method can produce more precise images and requires much less computational time than the FBP algorithm.