Indication and imaging of along-track moving targets in frequency modulated continuous wave synthetic aperture radar systems

Abstract

The spectrum of a moving target exhibits new characteristics in frequency modulated continuous wave (FMCW) synthetic aperture radar (SAR) systems. The new spectrum characteristics can be a favourable factor for ground moving target indication (GMTI) rather than being corrected as a phase error. In this letter, a novel algorithm is presented to indicate and focus along-track moving targets in FMCW SAR systems. Firstly, the signal model of an along-track moving target in FMCW SAR systems is derived. Secondly, the Hough transform is adopted to detect the along-track moving target by searching for its additional range walk and estimating its motion parameters. Finally, the target can be refocused and relocated in the stationary image. Simulation experiments offer evidences that the proposed algorithm is effective in the along-track moving target indication and imaging.