“一步一停”假设不成立时的星载聚束 SAR 成像

摘要

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.%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。