Processing Azimuth-Time Domain Aliasing in Spaceborne Sliding-Spotlight SAR Imaging

This paper proposes a modified two-step processing approach to deal with the problem of azimuth time domain aliasing in processing high resolution spaceborne sliding spotlight synthetic aperture radar (SAR) data. The signal model of spaceborne SAR is formulated, which includes the geometric model, echo model and Doppler bandwidth. This paper proposes a modified approach through parameter design to avoid azimuth-time domain aliasing. The sliding factor has a critical value for the azimuth-time aliasing, which meet the requirement of azimuth resolution and large imaging scene. The effectiveness of the proposed approach for sliding-spotlight SAR imaging is verified with simulation data for point targets.