Applying chirp-modulated back-projection to very high resolution spaceborne sliding spotlight SAR data processing

This paper proposed a new approach to focus the very high resolution spaceborne sliding spotlight synthetic aperture radar (SAR) data. The main singularity of the approach is accommodating the space dependent range histories by a back projection method on reduced apertures achieved by chirp modulation method. Besides, in the range spectrum domain, a dechirp method is employed to reduce the Doppler bandwidth to be within one PRF interval. Additionally, range splitting method is employed to mitigate the range dependence of effective velocities. Furthermore, the image grid is placed on the earth surface instead of the slant range plane, and the routine geometry projection processing becomes dispensable. The proposed approach was validated by simulation results of nine point targets.