NEAR-FIELD CROSS SECTION IMAGING BASED ON 2-D NUFFT FOR MILLIMETER WAVE

Near-field cross section imaging is an important issue in the area of near filed radar imaging. A conventional algorithm for cross section imaging is FFT after interpolation. It is intuitionistic and relatively fast. However the interpolation accuracy significantly affects the image quality especially when the data is highly curving in the case of wideband millimeter wave. To solve this problem, we propose an algorithm based on two-dimensional nonuniform fast Fourier transform (2-D NUFFT). It considers interpolation and FFT as a whole process and directly exploits the data collected over a linear array. The 2-D NUFFT is performed over the phase shifted 2-D spatial spectrum data to obtain the near-field images with high resolution. Experiments certify the effectiveness of this method, which can achieve more accurate near-field images with lower sidelobes than the conventional method.