Simplified Real‐Time Imaging Flow for High‐Resolution FMCW SAR

This letter considers the feasibility of a simplified real-time imaging flow theoretically for frequency-modulated continuous-wave synthetic aperture radar (FMCW SAR). The simplified imaging flow is based on the range-Doppler algorithm, whereas the simplifications contain absolving the residual-video-phase correction and performing the second-order motion compensation ahead of the range cell migration correction (RCMC). During the analysis, the platform movement within the transmission of a sweep is considered. Moreover, the hardware technique, i.e., the enhanced direct memory access, is used to improve the efficiency of the bulk RCMC. Eventually, the simplified imaging flow is evaluated in terms of quality and efficiency by using real Ku-band FMCW SAR data. The results indicate that the simplified method could produce SAR imagery of high resolution (0.25 m × 0.25 m) in real time, with a speed-up factor of 2.77 comparing with the frequency scaling algorithm.