Study on the improvements for the high-resolution frequency modulated continuous wave synthetic aperture radar imaging

This study develops two aspects of improvement, performing the range-dependent secondary range compression (SRC) and correcting the motion errors within the sweep of the transmitted signal, for the high-resolution frequency modulated continuous wave synthetic aperture radar (FMCW SAR). In cases of more complex imaging scenarios such as higher squint angle and larger range swath, the range dependence of SRC should be considered to avoid severe degradation. Moreover, when the trajectory deviations are severe, the motion error within the sweep causes new noticeable residual range cell migration, which should be considered for the motion compensation of FMCW SAR. Experimental results on the simulated and actual Ku-band SAR data proved that, for full swath and high squint mode FMCW SAR, the proposed approaches are valid and greatly helpful to improve the imaging quality.