“一步一停”假设不成立时的星载聚束SAR成像

Very-High-Resolution Spaceborne Spotlight SAR Imaging with the“Stop-and-Go”Assumption Invalid

对于星载超高分辨率合成孔径雷达(Synthetic Aperture Radar,SAR),回波生成时通常的"一步一停"假设不再成立,此时,常规的星载SAR成像方法将会造成目标成像质量的严重恶化。在星载SAR精确回波模型的基础上,提出了一种较为简便的、适用于星载超高分辨率聚束SAR成像的方法,该方法通过引入额外的距离徙动校正来补偿由于"一步一停"假设不成立所带来的信号畸变。仿真试验的结果表明,该成像方法能够很好地消除"一步一停"假设不成立的影响,实现精确的星载超高分辨率聚束SAR成像。

For very-high-resolution spaceborne SAR system, the common ＂stop-and-go＂ assumption is not valid any more, and the focusing of the targets will deteriorate greatly if the traditional SAR imaging al- gorithms are utilized. Based on the accurate spaceborne SAR echo model, a refined SAR imaging algorithm is proposed for very-high-resolution spaceborne spotlight SAR in this paper, which introduces an additional range migration correction to remove the signal aberration induced by the invalid ＂stop-and-go＂ assumption. Simulation results show that the proposed algorithm is effective to remove the influence of the ＂stop-and-go＂assumption and achieve accurate spaceborne spotlight SAR imagery.