Sparse Subband Imaging of Space Targets in High-Speed Motion

To achieve finer range resolution without increasing the bandwidth and sampling rate of the radar system, high-resolution imaging by data synthesizing using sparse subbands has received intensive attention in recent years. This paper derives the imaging geometry and signal model for radar imaging of space targets from sparse subbands. Next, it introduces and analyzes the available methods. Then, a practical method is proposed for sparse subband imaging of space targets in high-speed motion, which comprises phase compensation along the range and azimuth, gapped-data filling, scatterer number estimation, amplitude estimation, and azimuth image fusion. Finally, imaging of the simulated data using the fixed-point and electromagnetic scattering models proved the validity of the proposed method.