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遥感技术与应用  2020, Vol. 35 Issue (6): 1386-1393    DOI: 10.11873/j.issn.1004-0323.2020.6.1386
数据与图像处理     
基于改进CLEAN算法的FMCW ISAR低副瓣成像算法的研究
任佳伟1,2(),张祥坤1,2(),邵泽龙1,2
1.中国科学院国家空间科学中心 微波遥感技术重点实验室,北京 100190
2.中国科学院大学 电子电气与通信工程学院,北京 100049
Research on FMCW ISAR Low Sidelobe Imaging Technology based on Improved Clean Algorithm
Jiawei Ren1,2(),Xiangkun Zhang1,2(),Zelong Shao1,2
1.CAS Key Laboratory of Microwave Remote Sensing,National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China
2.University of Chinese Academy of Sciences,Beijing 100049,China
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摘要:

在调频连续波逆合成孔径雷达成像中,由于雷达发射信号带宽的有限性,雷达接收到的信号经过去调频,脉冲压缩后会呈现一系列等效点目标的二维sinc函数的叠加,所以合成孔径雷达成像不可避免的会受到sinc函数旁瓣叠加问题的影响,据此引进天文图像恢复中广泛使用的CLEAN算法。针对由于雷达实际成像环境的复杂性,以及目标的非匀速运动等导致的回波sinc函数旁瓣失真的问题,提出了在进行CLEAN算法之前先进行时域加窗加权修正旁瓣的方法,减小了不规则旁瓣对后续数据处理的影响。最后,对CLEAN算法中的“脏束”、“清洁波束”进行了修正,使其具有更强的目标检测能力及鲁棒性,提高了成像分辨率。对实测数据的处理表明,该方法对实际工程应用具有一定的参考价值。

关键词: 调频连续波逆合成孔径雷达旁瓣抑制改进CLEAN算法道路行车成像    
Abstract:

The Frequency Modulation Continuous Wave Inverse Synthetic Aperture Radar(FMCW ISAR) images by transmitting the Frequency Modulation Continuous Waves, due to the limited bandwidth of the transmitted waves, the imaging is affected by the sidelobes of the sinc function inevitably. The CLEAN algorithm is widely used in the astronomical images. In order to solve the problems of the sidelobes of the sinc function, the algorithm which combines of the windowing in time domain and the CLEAN algorithm is proposed, and improves the quality of the images obviously. Finally, the “dirty beam” and “clean beam” in the CLEAN algorithm are modified to improve the capacity of the radar detection. The results show that the proposed method has a certain reference for the applications.

Key words: Frequency Modulation Continuous Wave    Inverse Synthetic Aperture Radar    Sidelobe suppression    The improve of the CLEAN algorithm    Road vehicle imaging
收稿日期: 2019-01-15 出版日期: 2021-01-26
ZTFLH:  TN958.95  
通讯作者: 张祥坤     E-mail: renjiawei16@mails.ucas.ac.cn;zhangxiangkun@mirslab.cn
作者简介: 任佳伟(1992-),男,河北唐山人,硕士研究生,主要从事雷达成像、算法仿真及微波遥感系统研究。E?mail:renjiawei16@mails.ucas.ac.cn
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引用本文:

任佳伟,张祥坤,邵泽龙. 基于改进CLEAN算法的FMCW ISAR低副瓣成像算法的研究[J]. 遥感技术与应用, 2020, 35(6): 1386-1393.

Jiawei Ren,Xiangkun Zhang,Zelong Shao. Research on FMCW ISAR Low Sidelobe Imaging Technology based on Improved Clean Algorithm. Remote Sensing Technology and Application, 2020, 35(6): 1386-1393.

链接本文:

http://www.rsta.ac.cn/CN/10.11873/j.issn.1004-0323.2020.6.1386        http://www.rsta.ac.cn/CN/Y2020/V35/I6/1386

图1  ISAR回波信号模型
图2  Kaiser窗的时域频域特性
图3  小飞机旁瓣抑制仿真
图4  时域加窗后的仿真图
图5  应用CLEAN算法的仿真图
图6  加窗与CLEAN算法联合处理的效果图
图7  实验场景图
参数技术指标参数技术指标
中心频率36.05 GHz天线增益30 dB
扫频带宽300 MHz波束宽度4°×10°
发射功率23 dBm最大功率50 W
距离分辨率0.5 m重量<5 Kg
方位向分辨率6 cm
表1  FMCW ISAR系统参数
图8  CLEAN算法“脏束”的尖锐化处理
图9  成像结果的对比
平均均方误差峰值信噪比/dB
时域加窗19.89335.143
Clean 算法96.24928.296
改进clean算法19.81635.161
表2  重建图像效果参数
图10  距离向64处剖面对比
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