Non-linear Frequency Scaling Algorithm for FMCW SAR Data

This paper presents a novel approach for processing data acquired with frequency modulated continuous wave (FMCW) dechirp-on-receive systems by using a non-linear frequency scaling algorithm. The range frequency non-linearity correction, the Doppler shift induced by the continuous motion and the range migration removal are performed at the same time in the wavenumber domain with a very efficient solution. The cross-range focusing is then achieved with conventional matched filtering. Real data have been acquired with the FMCW SAR demonstrator system built at the Delft University of Technology. Stripmap images processed with the proposed method are presented in order to show the validity of the non-linear frequency scaling algorithm