Modified NCS Algorithm for High-Resolution Spaceborne Spotlight SAR Imaging

In this paper, the non-negligible high-order phases of space-borne synthetic aperture radar (SAR) echo signal in 2-D frequency domain are considered. Based on the advanced hyperbolic range model (AHRM), the analytic method is utilized to obtain the scaling factors together with the range frequency modulation (FM) rate involved in the processing functions. In doing so, a modified nonlinear chirp scaling (M-NCS) algorithm is proposed for high-resolution spaceborne spotlight SAR imaging. Point targets and scene imaging simulations validate the effectiveness of the proposed algorithm.