The near-field processing for a 2-D narrow imaging algorithm

This paper proposes a novel approximation for the round-trip distance of the near-field echoed data based on a planar 2-D synthetic aperture planar array. A near-field narrow imaging algorithm based on the novel approximation is proposed. Comparisons of the proposed approximation and the Fresnel approximation are also demonstrated. The errors of the proposed approximation are negligible when the antenna is fixed at (0, 0). In other cases, the errors decreased by almost 50 percent. Moreover, in our array system, narrow waveforms are employed, and thus, the range alignment and decoupling in range-azimuth are not necessary. The simulation results verify the validity of the algorithm.