Abstract:

Due to the problems of curved trajectory and real-time imaging requirement in the small synthetic aperture radar (SAR) platform, a sub-aperture algorithm is proposed for high squint mode SAR data focusing. First, the preprocessing is taken to remove the effect of acceleration on azimuth frequency modulation rate. After the preprocessing, the expressions of echo signals in 2D frequency domain are derived by the method of series reversion (MSR). Then, the space-variant of azimuth frequency modulation rate is corrected by azimuth frequency domain phase filtering (FDPF). Finally, the azimuth uniform focusing is done in the azimuth frequency domain by the spectrum analysis (SPECAN) technique. Simulation results validate the proposed algorithm.