基于快速分解后向投影算法的小天体快速三维成像  

Fast 3D Imaging of Small Solar System Bodies Based on FFBP Algorithm

作　　者：胡超然 韦明川 HU Chaoran;WEI Mingchuan(Research Center of Satellite Technology,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]哈尔滨工业大学卫星技术研究所,哈尔滨150001

出　　处：《数据采集与处理》2024年第2期312-323,共12页Journal of Data Acquisition and Processing

摘　　要：雷达成像技术凭借其快速、无损伤以及高分辨率的特点,在深空探测领域得到了日益广泛的关注。针对合成孔径雷达(Synthetic aperture radar,SAR)三维成像过程中运算效率低的问题,基于小天体弱引力和快速自旋的特点,提出了一种适用于慢飞越观测模式的快速分解后向投影(Fast factorized back-projection,FFBP)三维成像算法。首先,分析了慢飞越模式下的等效运动模型,基于运动模型将二维极坐标系成像域扩展至三维球坐标系成像域,对三维FFBP算法中的孔径划分以及图像融合问题进行了深入分析,推导了子孔径二维划分规则和图像递归融合方法,并给出了具体实现流程。最后通过数值仿真和实测数据验证了算法的有效性。实验结果表明,所提成像算法可大幅提升运算效率,根据不同的孔径划分方式,相较于后向投影(Back-projection,BP)算法,可实现30~50倍的加速比,并获得与经典BP算法近似的成像性能。Radar imaging technology has attracted increasing attention in the field of deep space exploration due to its fast,non-destructive,and high-resolution characteristics.To address the issue of low computational efficiency in synthetic aperture radar(SAR)3D imaging,a fast factorized back-projection(FFBP)3D imaging algorithm suitable for slow flyby observation modes is proposed leveraging the weak gravity and rapid spin characteristics of small solar system bodies.Initially,the equivalent motion model under slow flyby mode is analyzed,extending the imaging domain from a 2D polar coordinate system to a 3D spherical coordinate system.An in-depth analysis of aperture division and image fusion issues within the 3D FFBP algorithm is conducted,deriving rules for 2D sub-aperture division and recursive image fusion methods,along with a detailed implementation process.Finally,the effectiveness of the algorithm is validated through numerical simulations and measured data.Experimental results show that the proposed imaging algorithm significantly enhances computational efficiency.Compared to the back-projection(BP)algorithm,it can achieve a speedup ratio of 30—50 times while obtaining imaging performance comparable to the classical BP algorithm.

关 键 词：星载雷达 SAR三维成像 快速分解后向投影 太阳系小天体 深空探测 

分 类 号：TN957.52[电子电信—信号与信息处理] V11[电子电信—信息与通信工程]