Study on non-linear range-Doppler algorithm of FMCW SAR

Frequency-Modulated Continuous-Wave Synthetic Aperture Radar (FMCW SAR) is a compact, cost-effective and high-resolution remote sensing system. The Frequency non-linearities of FMCW SAR seriously deteriorate its range resolution. To overcome this problem and integrate the non-linearity correction method into the imaging algorithm, in this paper, we propose a non-linear range-Doppler algorithm for FMCW SAR. For practical application, the non-linearity error is truncated by neglecting the high-order terms, and the feasibility of this approximation is demonstrated. The Doppler shift induced by the continuous motion is also considered in the proposed algorithm. Finally, the efficiency of the proposed algorithm is verified with simulated FMCW SAR data.