| 摘要: |
| FMCW SAR是一种常见的雷达成像体制，其体积小、分辨率高等一系列特点使其非常适合作为自动驾驶系统中的传感器。针对传统成像方法存在方位分辨率不足问题和点稀疏模式下的成像不能有效利用扩展目标方位向结构特性问题，提出了一种基于块稀疏的扩展目标聚焦成像方法。该方法首先对运动补偿后的FMCW SAR回波数据进行距离压缩，通过一维恒虚警检测检测出有目标的距离单元，然后对有目标距离单元使用提出的块快速软阈值迭代算法（BFISTA）求解块稀疏问题进行方位向成像，最后通过近邻帧图像叠加实现对镜面反射的抑制与弱散射目标的聚焦成像。仿真与实验验证了该算法的有效性。 |
| 关键词: 车载合成孔径雷达 调频连续波 恒虚警检测 块稀疏 稀疏成像 |
| DOI：DOI:10.3969/j.issn.1672-2337.2023.06.013 |
| 分类号:TN958 |
| 基金项目:广西创新驱动发展专项（No.桂科 AA21077008）；广西无线宽带通信与信号处理重点实验室 2023年主任基金；桂林电子科技大学研究生教育创新计划项目（No.2022YCXS028） |
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| Extended Target Focusing Imaging Method for Automotive Millimeter Wave FMCW SAR |
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YUAN Mengbei， JIN Liangnian
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1. School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China;2. Guangxi Key Laboratory of Wireless Broadband Communication and Signal Processing, Guilin 541004, China
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| Abstract: |
| FMCW SAR is a common radar imaging system. Its small size and high resolution make it very suitable for use as a sensor in automatic driving system. Aiming at the problem of insufficient azimuth resolution in traditional imaging methods and the insufficient utilization of the azimuth structural characteristics in point sparse imaging mode, a focusing imaging method for extended targets based on block sparse is proposed. The method firstly carries out the range compression on motion compensated FMCW SAR echo data, and the range cell with targets is detected by one?dimensional CFAR detection. Then the azimuth imaging of the range cell with targets is realized by solving the block sparse problem using the proposed block fast iterative soft threshold algorithm （BFISTA）. Finally, the suppression of specular reflection and the focusing of weak scattering targets are achieved by the superposition of adjacent frame images. The effectiveness of the proposed algorithm is verified through simulation and experiments. |
| Key words: automotive SAR FMCW CFAR block sparse sparse imaging |
