高轨SAR精细成像系统设计和实现

    High orbit SAR precision imaging system design and realization

    • 摘要: 高轨合成孔径雷达(SAR)具有轨道高度高、合成孔径时间长、斜视观测和成像幅宽大等特点,在成像处理时面临超长时间相干积累、轨道弯曲大、频谱二维耦合严重、成像参数时空变严重、大气传输误差影响大和数据量剧增的难题。文章针对上述难题,综合考虑轨道、对流层、电离层和高程等误差源的影响校正,设计实现了一套高轨SAR精细成像系统,提出一种分布式子景成像方案,并通过多级功能模块构建,完成高轨SAR高精度快速成像,最终实现高轨SAR标准产品的生产和输出。仿真实验验证了所提系统的处理能力。

       

      Abstract: High-orbit synthetic aperture radar (SAR), characterized by high orbital altitude, long synthetic aperture time, and large imaging width, faces challenges such as ultra-long time coherent accumulation, large track curvature, severe spectral two-dimensional coupling, strong temporal and spatial variation of imaging parameters, large influence of atmospheric transmission errors and a dramatic increase in data volume during imaging processing. To address the aforementioned issues, a high-orbit SAR precision imaging system was designed and implemented. This system comprehensively considers the correction of error sources such as orbit, troposphere, ionosphere, and elevation. It proposes a distributed sub-scene imaging scheme and completes high-precision and rapid imaging of high-orbit SAR through the construction of multilevel function modules. Ultimately, this system produces and outputs standard products of high-orbit SAR. Simulation experiments verify the processing capability of the proposed system.