Study on the echo signal model and R-D imaging algorithm for FMCW SAR

Frequency modulation continuous wave (FMCW) is often applied in miniature synthetic aperture radar (MINI SAR) . FMCW SAR sends linear frequency modulated (LFM) continuous wave signal with wide band, and the receiving echo of targets mixes with the sending signal. Therefore, the echo for imaging processing can be sampled in intermediate frequency (IF) band with low sampling rate, and the system can keep small and light. After imaging processing with the echos, FMCW SAR can obtain the image of the target with high resolution. In this paper, the observation geometry and the echo signal model of FMCW SAR are analyzed. Range-Doppler (R-D) algorithm for FMCW SAR imaging is deduced. Finally, the simulation experiments with R-D algorithm for point targets are given.