2D Resolution Coherent Enhancement of Distributed Spaceborne SAR

Distributed spaceborne synthetic aperture radar (SAR) can discern the intricate details of target structures and precisely characterize them. It uniquely excels in fields like ultra-high-resolution imaging, multi-view coherent fusion, moving target detection, and target recognition. This paper investigates the coherent enhancement of the two-dimensional resolution of SAR in both azimuth and range under distributed spaceborne platforms. In the multi-sub-band distribution pattern of overlapping frequency spectra along the range direction, the joint channel error from overlapping frequency bands is employed to estimate and compensate for inter-sub-band errors, and the bandwidth is synthesized to enhance range resolution coherently. Subsequently, for multi-aperture distribution patterns with azimuthal gaps, a method based on compressive sensing is proposed for sparse recovery of the gap data. This approach effectively elevates azimuth resolution and suppresses spurious targets in the azimuth direction.