Abstract:Based on the forward-squint-looking SAR mode of SAR system, this paper gives the mathematical model of SAR echo signal, and carefully analyses the instantaneous azimuth frequency , the instantaneous Doppler frequency component of the azimuth frequency and the impact of range chirp on azimuth frequency, then combining with the common chirp scal-ing algorithms, proposes an improved chirp scaling algorithm for forward-squint-looking SAR, imaging, and takes the simulated test with the algorithm. The results of theory and simula-tion show that the way is more reasonable for forward-squint-looking SAR geometric relation and can effectively complete range cell migration correction, range compression and azimuth focusing, and improve images’ quality.