A Modified Frequency Scaling Algorithm for Highly Squinted FMCW-SAR Mounted on Maneuvering Platforms

This article proposes a new method for FMCW- SAR installed on highly squinted maneuvering platforms. A modified range walk correction method was proposed to solved the additive component of the range azimuth coupling. Then, in order to correct the space variation in azimuth time domain of the frequency scaling component, an improved fourth-order frequency scaling function and remaining video phase correction function is proposed. Finally, the azimuth frequency-domain nonlinear chirp scaling function is used to correct the azimuth space variation of Doppler parameters and complete azimuth focusing. Finally, we validated the effectiveness of the proposed MFSA through simulation of SAR point targets with highly squint angle.