基于参数估计的高分辨率SAR运动目标距离徙动校正方法
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摘要
距离徙动校正(RCMC)是机载单天线高分辨率合成孔径雷达(SAR)实现运动目标聚焦成像的关键环节。针对现有方法运算量大、精度低的缺点,该文提出一种结合参数估计分4步完成的RCMC方法。该方法首先通过结合能量均衡法的Hough变换估计距离向速度并校正距离走动,然后以初始方位向调频率校正距离弯曲,再采用Map-drift估计精确的方位向调频率,最后校正残余距离弯曲。与传统方法相比,该方法计算量较小,性能稳定,并能够校正高分辨率下不可忽略的残余距离弯曲。该文给出新方法的数学模型,并通过仿真和实际数据处理验证了该方法的有效性。
Range Cell Migration Correction(RCMC) represents an important advance in moving target imaging in the airborne single antenna high-resolution SAR system. In this paper, we propose a new four-step RCMC approach combined with parameter estimation that overcomes the drawbacks of high computation and low accuracy in high-resolution. First, we use the Hough transform and the energy balancing method to estimate the range velocity and correct the range walk. Next, we perform a range curvature correction in the rangeDoppler domain by using the initial Doppler rate. Thirdly, we accurately estimate the Doppler rate using Mapdrift technology. Finally, we correct the residual range curvature by the accurate Doppler rate. Compared with traditional algorithms, the proposed method requires less computation and is robust in the high-resolution SAR system. In this paper, we present a mathematical model and validate its effectiveness using both simulation and real data.
Range Cell Migration Correction(RCMC) represents an important advance in moving target imaging in the airborne single antenna high-resolution SAR system. In this paper, we propose a new four-step RCMC approach combined with parameter estimation that overcomes the drawbacks of high computation and low accuracy in high-resolution. First, we use the Hough transform and the energy balancing method to estimate the range velocity and correct the range walk. Next, we perform a range curvature correction in the rangeDoppler domain by using the initial Doppler rate. Thirdly, we accurately estimate the Doppler rate using Mapdrift technology. Finally, we correct the residual range curvature by the accurate Doppler rate. Compared with traditional algorithms, the proposed method requires less computation and is robust in the high-resolution SAR system. In this paper, we present a mathematical model and validate its effectiveness using both simulation and real data.
引文
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[10]汤立波.高分辨率机载SAR地面/海面运动目标成像技术研究[D].[博士论文],中国科学院电子学研究所,2006:53-54.TANG Li-bo.Imaging techniques of ground/sea moving targets for high resolution airborne SAR[D].[Ph.D.dissertation],Institute of Electrics,Chinese Academy of Sciences,2006:53-54.
[11]CUMMING I G and WONG F H.Digital Processing of Synthetic Aperture Radar Data:Algorithms and Implementation[M].Boston:Artech House Publishers,2005:337,165.
[12]CANTALLOUBE H M J and NAHUM C E.Multiscale local map-drift-driven multilateration SAR autofocus using fast polar format image synthesis[J].IEEE Transactions on Geoscience and Remote Sensing,2011,49(10):3730-3736.doi:10.1109/TGRS.2011.2161319.
[13]WAHL D E,EICHEL P H,GHIGLIA D C,et al.Phase gradient autofocus-A robust tool for high resolution SARphase correction[J].IEEE Transactions on Aerospace and Electronic Systems,1994,30(3):827-835.doi:10.1109/7.303752.
[14]FREEMAN A and CURRIE A.Synthetic aperture radar(SAR)images of moving targets[J].GEC Journal of Research,1987,5(2):106-115.doi:10.1117/12.932852.
[2]周峰,李亚超,邢孟道,等.一种单通道SAR地面运动目标成像和运动参数估计方法[J].电子学报,2007,35(3):543-548.doi:10.3321/j.issn:0372-2112.2007.03.033.ZHOU Feng,LI Ya-chao,XING Meng-dao,et al.An effective approach to ground moving target imaging and motion parameter estimation for single channel SARsystem[J].Acta Electronica Sinica,2007,35(3):543-548.doi:10.3321/j.issn:0372-2112.2007.03.033.
[3]汤立波,李道京,吴一戎,等.机载SAR的地面运动目标成像处理[J].系统工程与电子技术,2005,27(10):1681-1684.doi:10.3321/j.issn:1001-506X.2005.10.004.TANG Li-bo,LI Dao-jing,WU Yi-rong,et al.Imaging of ground moving targets based on airborne SAR[J].Systems Engineering and Electronics,2005,27(10):1681-1684.doi:10.3321/j.issn:1001-506X.2005.10.004.
[4]PERRY R P,DIPIETRO R C,and FANTE R L.SARimaging of moving targets[J].IEEE Transactions on Aerospace and Electronic Systems,1999,35(1):188-200.doi:10.1109/7.745691.
[5]ZHOU F,WU R B,XING M D,et al.Approach for single channel SAR ground moving target imaging and motion parameter estimation[J].IET Radar,Sonar&Navigation,2007,1(1):59-66.doi:10.1049/iet-rsn.20060040.
[6]范健华,李春林.基于FPGA的Keystone变换算法设计和实现[J].电子科技,2016,29(6):54-57.doi:10.16180/j.cnki.issn1007-7820.2016.06.016.FAN Jian-hua and LI Chun-lin.Design and implementation of Keystone transform based on FPGA[J].Electronic Science and Technology,2016,29(6):54-57.doi:10.16180/j.cnki.issn1007-7820.2016.06.016.
[7]CAO Y F,QU X G,and HUANG P K.Research on Keystone formatting based on non-baseband interpolation[J].Journal of Systems Engineering and Electronics,2010,21(4):562-565.doi:10.3969/j.issn.1004-4132.2010.04.006.
[8]朱圣棋,廖桂生,曲毅,等.机载正侧视合成孔径雷达地面运动目标参数估计方法[J].电子学报,2010,38(12):2757-2762.ZHU Sheng-qi,LIAO Gui-sheng,QU Yi,et al.An approach of ground moving target motion parameter estimation for airborne sidelooking SAR system[J].Acta Electronica Sinica,2010,38(12):2757-2762.
[9]LI Y K,WANG Y F,and LIU C.Detect and autofocus the moving target by its range walk in time domain[C].Proceedings of 2011 International Conference on Wireless Communications and Signal Processing,Nanjing,2011:1-5.doi:10.1109/WCSP.2011.6096755.
[10]汤立波.高分辨率机载SAR地面/海面运动目标成像技术研究[D].[博士论文],中国科学院电子学研究所,2006:53-54.TANG Li-bo.Imaging techniques of ground/sea moving targets for high resolution airborne SAR[D].[Ph.D.dissertation],Institute of Electrics,Chinese Academy of Sciences,2006:53-54.
[11]CUMMING I G and WONG F H.Digital Processing of Synthetic Aperture Radar Data:Algorithms and Implementation[M].Boston:Artech House Publishers,2005:337,165.
[12]CANTALLOUBE H M J and NAHUM C E.Multiscale local map-drift-driven multilateration SAR autofocus using fast polar format image synthesis[J].IEEE Transactions on Geoscience and Remote Sensing,2011,49(10):3730-3736.doi:10.1109/TGRS.2011.2161319.
[13]WAHL D E,EICHEL P H,GHIGLIA D C,et al.Phase gradient autofocus-A robust tool for high resolution SARphase correction[J].IEEE Transactions on Aerospace and Electronic Systems,1994,30(3):827-835.doi:10.1109/7.303752.
[14]FREEMAN A and CURRIE A.Synthetic aperture radar(SAR)images of moving targets[J].GEC Journal of Research,1987,5(2):106-115.doi:10.1117/12.932852.