Ambiguity Resolving and Imaging Algorithm for Multi-channel Forward-looking Synthetic Aperture Radar
-
摘要: 传统合成孔径雷达方位向分辨率仅由合成孔径提供，但在正前视区域多普勒分集有限，成像性能迅速下降且前视成像也存在固有的左右多普勒模糊问题。针对上述问题该文讨论前视多通道合成孔径雷达系统模型，提出一种理想直线航迹下空域零点约束自适应波束形成的成像方法，有效综合阵列实孔径和合成孔径提高正前视区域的成像质量，利用有限阵列空域自由度实现左右多普勒解模糊。首先对回波数据大前斜成像处理，得到左右模糊的图像，然后进行波束形成，将各通道图像加权并且相干累加，实现左右多普勒解模糊以及方位分辨率增强。仿真实验表明空域零点约束自适应波束形成的成像方法可对前视场景进行高分辨成像。Abstract: The azimuth resolution of traditional synthetic aperture radar is only provided by synthetic aperture. However, in the forward looking area, the Doppler diversity is limited, so the imaging performance declines rapidly. And forward looking imaging also has the Doppler ambiguity problem. In this paper, an adaptive beam forming method with spatial confinement under ideal line track is proposed. The imaging quality of the positive forward region is improved effectively by combining the array of real aperture and synthetic aperture, and the Doppler solution is blurred by using the array space domain. First, the echo data is processed by High Squint SAR imaging to obtain the blurred image. Then the beam-forming is performed, weighted and coherent accumulated with each channel image, so as to resolve Doppler ambiguity and enhance the azimuth resolution. Simulation confirms the validity of the proposed approach.
-
Key words:
- SAR /
- Forward-looking imaging /
- Azimuth resolution /
- Doppler ambiguity /
- Beam forming
-
表 1 仿真参数
参数 数值 参数 数值 载频Fc 30 GHz 脉冲重复频率PRF 8000 Hz 信号带宽B 55 MHz 波束方位宽度 8° 采样带宽Fs 64 MHz 波束俯仰宽度 22° 下压角 20° 场景中心斜距Rs 7000 m 合成孔径长度 100 m 阵列实孔径长度 0.4 m 
下载: 导出CSV
表 2 各方位点目标仿真分辨率与理论分辨率对比
参数 数值 数值 数值 数值 数值 坐标 (R0, 3.4°) (R0, –3.0°) (R0, 2.6°) (R0, 2.2°) (R0, 1.8°) 仿真分辨率IRW(rad) 6.76E–04 7.63E–04 8.72E–04 1.13E–03 1.53E–03 理论全孔径分辨率(rad) 7.00E–04 7.91E–04 9.09E–04 1.07E–03 1.29E–03 理论合成孔径分辨率(rad) 7.50E–04 8.55E–04 9.94E–04 1.19E–03 1.46E–03
下载: 导出CSV
-
WU Xiaoli and WANG Weiwei. The burst mode of geosynchronous Synthetic Aperture Radar[C]. IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar, Piscataway, USA, 2015: 200–203. LI Caipin and HE Mingyi. A novel attitude steering strategy for GEO SAR staring Imaging[C]. IEEE China Summit and International Conference on Signal and Information Processing, Piscataway, USA, 2015: 630–634. RODRIGUEZ M, PRATS P, SCHULZE D, et al. First bistatic spaceborne SAR experiments with TanDEM-X[J]. IEEE Geoscience and Remote Sensing Letters, 2012, 9(1): 33–37. INGO W, THOMAS E, and JENS K, et al. Potential and limitations of forward-looking bistatic SAR[C]. IEEE International Geoscience and Remote Sensing Symposium, Piscataway, USA, 2010: 216–219. 孟自强, 李亚超, 邢孟道, 等. 基于斜距等效的弹载双基前视SAR相位空变校正方法[J]. 电子与信息学报, 2016, 38(3): 613–621 doi: 10.11999/JEIT150782MENG Ziqiang, LI Yachao, XING Mengdao, et al. Phase space-variance correction method for missile-borne bistatic forward-looking sar based on equivalent range equation[J]. Journal of Electronics&Information Technology, 2016, 38(3): 613–621 doi: 10.11999/JEIT150782 REN Xiaozhen, SUN Jiantao, YANG Ruliang, et al. A new three-dimensional imaging algorithm for airborne forward-looking SAR[J]. IEEE Geoscience and Remote Sensing Letters, 2011, 8(1): 153–157 doi: 10.1109/LGRS.2010.2055035 SUTOR T, BUCKREUSS S, KRIEGER G, et al. Sector imaging radar for enhanced vision: theory and applications[C]. European Conference on Synthetic Aperture Radar, Munich, Germany, 2000: 357–359. 包敏, 周鹏, 史林, 等. 双天线前视弹载SAR解模糊算法研究[J]. 电子与信息学报, 2013, 35(12): 2857–2862 doi: 10.3724/SP.J.1146.2013.00083BAO Min, ZHOU Peng, SHI Lin, et al. Study on deambiguity algorithm for double antenna forward looking missile borne SAR[J]. Journal of Electronics&Information Technology, 2013, 35(12): 2857–2862 doi: 10.3724/SP.J.1146.2013.00083 李悦丽, 梁甸农, 黄晓涛, 等. 一种单脉冲雷达多通道解卷积前视成像方法[J]. 信号处理, 2007, 23(5): 699–703LI Yueli, LIANG Diannong, HUANG Xiaotao et al. A multi-channel deconvolution based forward-looking imaging method in monopulse radar[J]. Signal Processing, 2007, 23(5): 699–703 曾操, 陈昊, 何学辉, 等. 相控阵子阵级和差多波束测角方法[J]. 西安电子科技大学学报, 2013, 40(1): 19–25 doi: 10.3969/j.issn.1001-2400.2013.01.004ZENG Cao, CHEN Hao, HE Xuehui et al. Monpulse angle estimation using sun-difference multi-beamforming based on the phase array at the sub-array level[J]. Journal of Xidian University, 2013, 40(1): 19–25 doi: 10.3969/j.issn.1001-2400.2013.01.004 赵珊珊, 张林让, 刘楠, 等. 利用幅度比特征进行有源假目标鉴别[J]. 西安电子科技大学学报, 2017, 44(5): 51–57 doi: 10.3969/j.issn.1001-2400.2017.05.009ZHAO Shanshan, ZHANG Linrang, LIU Nan, et al. Active false-target discrimination method based on the amplitude ratio feature[J]. Journal of Xidian University, 2017, 44(5): 51–57 doi: 10.3969/j.issn.1001-2400.2017.05.009 韦北余, 朱岱寅, 吴迪, 等. 一种基于和差波束的机载SAR定位方法[J]. 电子与信息学报, 2013, 35(6): 1464–1470 doi: 10.3724/SP.J.1146.2012.01194WEI Beiyu, ZHU Daiyin, WU Di, et al. An airborne SAR geolocation approach based on sum-difference beam SAR imagery[J]. Journal of Electrontics&Information Technology, 2013, 35(6): 1464–1470 doi: 10.3724/SP.J.1146.2012.01194 马晓峰, 沈爱松, 盛卫星, 等. 可控测角精度和范围的数字阵列单脉冲和差波束优化[J]. 电子与信息学报, 2016, 38(12): 3107–3113 doi: 10.11999/JEIT160873MA Xiaofeng, SHEN Aisong, SHENG Weixing et al. Sum and difference patterns optimization for digital array with controllable accuracy and range of angle estimation[J]. Journal of Electronics&Information Technology, 2016, 38(12): 3107–3113 doi: 10.11999/JEIT160873 温鑫, 黄培康, 年丰, 等. 主动式毫米波近距离圆柱扫描三维成像系统[J]. 系统工程与电子技术, 2004, 36(6): 1044–1049WEN Xin, HUANG Peikang, NIAN Feng et al. Active millimeter-wave near-field cylindrical scanning three-dimensional imaging system[J]. Systems Engineering and Electronics, 2004, 36(6): 1044–1049 马喜乐. 方位多相位中心SAR高分辨率宽测绘带成像技术研究[D]. [博士论文], 国防科技大学, 2014.MA Xile. Research on high-resolution wide-swath imaging technologies of azimuth multiple phase center SAR[D]. [Ph.D. dissertation], National University of Defense Technology, 2014. -
图(4) / 表(2)
计量
- 文章访问数: 2472
- HTML全文浏览量: 815
- PDF下载量: 90
- 被引次数: 0
下载:
