It is very difficult to detect micro-motion targets against a strong ground clutter background. In order to solve this problem, this paper proposes respectively the methods of dual-channel synthetic aperture radar/displaced phase center antenna (SAR/DPCA) and along-track interferometry (ATI) based on a detailed study of the echo features of rotating targets in the range-compressed data domain. Under the mode of SAR/DPCA, the entire micro-Doppler (m-D) signature undergoes a shift along the frequency axis which is proportional to the azimuth position of the revolving center. Therefore, the target can be located while the micro-motion parameters are estimated. Under the mode of SAR/ATI, the m-D signature cannot be directly obtained from the imaginary part of the interferometric signal by time-frequency transform, so a method is proposed of reconstructing the complex signal of a rotating target based on the imaginary part. In order to avoid m-D ambiguity, the paper points out that when the length of baseline is comparatively short, the method of SAR/ATI is more suitable for detecting targets with big rotating blades than the method of SAR/DPCA, because it requires lower pulse repetition frequency (PRF), The results of simulation tests for these modes testify the validity of the theoretical analysis and the proposed methods.
ZHANG Wei, TONG Chuangming, ZHANG Qun, ZHANG Ya'nan
. Rotating Targets Detection with Dual-channel SAR Based on Time-frequency Analysis[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2011
, 32(10)
: 1914
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DOI: CNKI:11-1929/V.20110707.1107.004
[1] Gabele M, Brautigam B, Schulze D, et al. Fore and aft channel reconstruction in the TerraSAR-X dual receive antenna mode[J]. IEEE Transactions on Geoscience and Remote Sensing, 2010, 48(2): 795-806.
[2] 钱江, 吕孝雷, 刑孟道, 等. 机载三通道SAR/GMTI快速目标运动参数估计[J]. 西安电子科技大学学报, 2010, 37(2): 235-241. Qian Jiang, Lü Xiaolei, Xing Mengdao, et al. Parameter estimation of the fast moving target based on tri-channel airborne SAR-GMTI[J]. Journal of Xidian University, 2010, 37(2): 235-241. (in Chinese)
[3] Chen V C, Li F, Ho S -S, et al. Micro-Doppler effect in radar: phenomenon, model, and simulation study[J]. IEEE Transactions on Aerospace and Electronic Systems, 2006, 42(1): 2-21.
[4] 庄钊文, 刘永祥, 黎湘. 目标微动特性研究进展[J]. 电子学报, 2007, 35(3): 520-525. Zhuang Zhaowen, Liu Yongxiang, Li Xiang. The achievements of target characteristic with micro-motion[J]. Acta Electronica Sinica, 2007, 35(3): 520-525. (in Chinese)
[5] Zhang Q, Yeo T S, Tan H S, et al. Imaging of a moving target with rotating parts based on the Hough transform[J]. IEEE Transactions on Geoscience and Remote Sensing, 2008, 46(1): 291-299.
[6] 白雪茹, 周峰, 邢孟道, 等. 空中微动旋转目标的二维ISAR成像算法[J]. 电子学报, 2009, 37(9): 1937-1943. Bai Xueru, Zhou Feng, Xing Mengdao, et al. 2D ISAR imaging algorithm for air micro-motion targets[J]. Acta Electronica Sinica, 2009, 37(9): 1937-1943. (in Chinese)
[7] 黄小红, 贺夏, 辛玉林, 等. 基于时频特征的低分辨雷达微动多目标分辨方法[J]. 电子与信息学报, 2010, 32(10): 2342-2347. Huang Xiaohong, He Xia, Xin Yulin, et al. Resolving multiple targets with micro-motions based on time-frequency feature with low-resolution radar[J]. Journal of Electronics & Information Technology, 2010, 32(10): 2342-2347. (in Chinese)
[8] 刘进, 王雪松, 马梁, 等. 空间进动目标动态散射特性的实验研究[J]. 航空学报, 2010, 31(5): 1014-1023. Liu Jin, Wang Xuesong, Ma Liang, et al. Experimental study on dynamic scattering properties of space precession target[J]. Acta Aeronautica et Astronautica Sinica, 2010, 31(5): 1014-1023. (in Chinese)
[9] Sparr T, Krane B. Micro-Doppler analysis of vibrating targets in SAR[J]. IEE Proceeding Radar Sonar Navigation, 2003, 150(4): 277-283.
[10] Rüegg M, Meier E, Nuesch D. Vibration and rotation in millimeter-wave SAR[J]. IEEE Transactions on Geoscience and Remote Sensing, 2007, 45(2): 293-304.
[11] 吴晓芳, 刘阳, 王雪松, 等. 旋转微动目标的SAR成像特性分析[J]. 宇航学报, 2010, 31(4): 1181-1189. Wu Xiaofang, Liu Yang, Wang Xuesong, et al. Analysis of SAR imaging characteristics of targets with rotational micro-motion[J]. Journal of Astronautics, 2010, 31(4): 1181-1189. (in Chinese)
[12] Muehe C E, Labitt M. Displaced-phase-center antenna technique[J]. Lincoln Laboratory Journal, 2000, 12(2): 281-296.
[13] Suchandt S, Runge H, Breit H, et al. Automatic extraction of traffic flows using TerraSAR-X along-track interferometry[J]. IEEE Transactions on Geoscience and Remote Sensing, 2010, 48(2): 807-819.
[14] 郑明洁, 杨汝良. 双通道沿迹干涉SAR地面动目标检测[J]. 电子与信息学报, 2005, 27(10): 1561-1563. Zheng Mingjie, Yang Ruliang. Dual channels along-track interferometry SAR ground moving target detection[J]. Journal of Electronics & Information Technology, 2005, 27(10): 1561-1563. (in Chinese)
[15] 高红卫, 谢良贵, 文树梁, 等. 摆动锥体目标微多普勒分析和提取[J]. 电子学报, 2008, 36(12): 2497-2502. Gao Hongwei, Xie Lianggui, Wen Shuliang, et al. Analysis and extraction of micro-Doppler induced by cone-shaped target's wobbling[J]. Acta Electronica Sinica, 2008, 36(12): 2497-2502. (in Chinese)
[16] 彭海良, 王彦平. 地形测绘用三天线机载干涉合成孔径雷达[J]. 现代雷达, 2006, 28(10): 70-74. Peng Hailiang, Wang Yanping. A tri-antenna airborne interferometric synthetic aperture radar for topographic mapping[J]. Modern Radar, 2006, 28(10): 70-74. (in Chinese)
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