干涉SAR测高测速技术研究
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摘要
干涉合成孔径雷达(InSAR)是合成孔径雷达(SAR)功能的扩展,有两种工作模式:切航迹干涉(CT-InSAR)和沿航迹干涉(AT-InSAR),其中切航迹干涉具有获取地面高程的能力,沿航迹干涉具有检测地面慢速运动目标的能力。由于InSAR测量精度高以及全天候、全天时工作的特点,有着巨大的军用与民用价值,是目前SAR领域研究的热点之一。本文主要研究了InSAR技术中几个关键性的问题,如CT-InSAR中的图像配准、AT-InSAR中的运动目标检测及运动速度估计等,最后研究了混合基线下InSAR的相位分离问题。
本文的主要工作有:
1、详细阐述InSAR高程测量及运动目标检测的基本原理。给出了CT-InSAR的数学模型,指出在一定近似的条件下,干涉相位和高程之间存在线性关系;然后分析了AT-InSAR运动目标的回波模型,并对已有的检测方法作了分类和简要介绍。
2、研究了CT-InSAR自适应图像配准的干涉相位估计方法。该方法的特点是将图像配准和干涉相位估计同时进行。文章在给出其数学模型及处理步骤的基础上,对方法作了改进,并用SIR-C/X-SAR实测数据对改进后的效果进行了验证。
3、研究了基于协方差矩阵的运动目标检测方法。分析了小特征值法和非对角元素幅度差法,并提出一种基于协方差矩阵条件数的方法。与传统方法相比,该类方法的优点是杂波抑制效果好,但运算量稍大。
4、研究了DPCA和DCFT相结合的运动目标运动速度估计方法。在DPCA检测出运动目标的基础上,用基于能量熵的DCFT估计出其多普勒参数,然后根据这些参数和运动速度之间的关系,可以得到目标的距离向和方位向速度。
5、研究了混合基线情况下InSAR的相位分离问题。为了同时实现测高测速,可以将InSAR基线混合偏置,然后将所得到的干涉相位分离即可。文章推导了理论模型并通过计算机仿真对分离的可行性进行了验证,并指出在这种情况下可以先用基于协方差矩阵的运动目标检测方法检测出运动目标,然后再相位分离。
Interferometric synthetic aperture radar (InSAR) is function expansion of synthetic aperture radar (SAR). It includes two work modes: cross track interferometry SAR (CT-InSAR) and along track interferometry SAR (AT-InSAR). CT-InSAR can get the goal ground’s elevation, and AT-InSAR can realize ground slow moving target detection. Because of its high precision measurement and may work in all weather and all day, InSAR has great value in military and civil, so it has become one of the focuses of research in the SAR field. This dissertation mainly studies several crucial issues in InSAR technologies, such as image coregistration in CT-InSAR, moving target detection and estimation of motion parameters in AT-InSAR. Finally, Phase separation in InSAR with hybrid baseline is studied.
The major work of this dissertation is as follows:
1、Basic principles of SAR elevation measurement and ground moving target detection are detailed. First, mathematical model of CT-InSAR is introduced. The dissertation points out that under certain approximative conditions, a linear relationship exists between the interferometric phase and the elevation. Then the dissertation analyzes the model of moving targets’echoes in AT-InSAR, classificates and briefly introduces the detection methods that have been proposed.
2、An estimation method for CT-InSAR interferometric phase with adaptive image coregistration is studied. The characteristic of this method is that image coregistration and interferometric phase estimation are done at the same time. The dissertation gives the method’s mathematical model and processing steps, then improves it. Finally, the effectiveness of the improved method is verified with the real data from SIR-C/X–SAR.
3、A moving target detection method base on the covariance matrix is studied. The dissertation firstly introduces the methods that have been proposed, such as small values, magnitude difference of non-diagonal elements, then a method based on the covariance matrix eigenvalue ratio is proposed. The dissertation compares these methods with traditional ones, and points out that such method has effective clutter suppression, while computation is larger.
4、An estimation method for moving targets’velocities based on the combination of DPCA and DCFT is studied. The moving targets’Doppler parameters can be estimated with DCFT which is based on energy entropy. Then according to the relationship between these parameters and moving target’s velocities, the range velocity and azimuth velocity can be estimated.
5、Phase separation in InSAR with hybrid baseline is studied. In order to obtain elevation and velocities at the same time, we can tilt the baseline, then measure elevation and velocities by separating the hybrid phase. The dissertation derives the theoretical model and verifies the feasibility of this method through a simulation on the computer, then points out that in such case, moving targets can be detected firstly by methods based on the covariance matrix, then the phase can separated.
本文的主要工作有:
1、详细阐述InSAR高程测量及运动目标检测的基本原理。给出了CT-InSAR的数学模型,指出在一定近似的条件下,干涉相位和高程之间存在线性关系;然后分析了AT-InSAR运动目标的回波模型,并对已有的检测方法作了分类和简要介绍。
2、研究了CT-InSAR自适应图像配准的干涉相位估计方法。该方法的特点是将图像配准和干涉相位估计同时进行。文章在给出其数学模型及处理步骤的基础上,对方法作了改进,并用SIR-C/X-SAR实测数据对改进后的效果进行了验证。
3、研究了基于协方差矩阵的运动目标检测方法。分析了小特征值法和非对角元素幅度差法,并提出一种基于协方差矩阵条件数的方法。与传统方法相比,该类方法的优点是杂波抑制效果好,但运算量稍大。
4、研究了DPCA和DCFT相结合的运动目标运动速度估计方法。在DPCA检测出运动目标的基础上,用基于能量熵的DCFT估计出其多普勒参数,然后根据这些参数和运动速度之间的关系,可以得到目标的距离向和方位向速度。
5、研究了混合基线情况下InSAR的相位分离问题。为了同时实现测高测速,可以将InSAR基线混合偏置,然后将所得到的干涉相位分离即可。文章推导了理论模型并通过计算机仿真对分离的可行性进行了验证,并指出在这种情况下可以先用基于协方差矩阵的运动目标检测方法检测出运动目标,然后再相位分离。
Interferometric synthetic aperture radar (InSAR) is function expansion of synthetic aperture radar (SAR). It includes two work modes: cross track interferometry SAR (CT-InSAR) and along track interferometry SAR (AT-InSAR). CT-InSAR can get the goal ground’s elevation, and AT-InSAR can realize ground slow moving target detection. Because of its high precision measurement and may work in all weather and all day, InSAR has great value in military and civil, so it has become one of the focuses of research in the SAR field. This dissertation mainly studies several crucial issues in InSAR technologies, such as image coregistration in CT-InSAR, moving target detection and estimation of motion parameters in AT-InSAR. Finally, Phase separation in InSAR with hybrid baseline is studied.
The major work of this dissertation is as follows:
1、Basic principles of SAR elevation measurement and ground moving target detection are detailed. First, mathematical model of CT-InSAR is introduced. The dissertation points out that under certain approximative conditions, a linear relationship exists between the interferometric phase and the elevation. Then the dissertation analyzes the model of moving targets’echoes in AT-InSAR, classificates and briefly introduces the detection methods that have been proposed.
2、An estimation method for CT-InSAR interferometric phase with adaptive image coregistration is studied. The characteristic of this method is that image coregistration and interferometric phase estimation are done at the same time. The dissertation gives the method’s mathematical model and processing steps, then improves it. Finally, the effectiveness of the improved method is verified with the real data from SIR-C/X–SAR.
3、A moving target detection method base on the covariance matrix is studied. The dissertation firstly introduces the methods that have been proposed, such as small values, magnitude difference of non-diagonal elements, then a method based on the covariance matrix eigenvalue ratio is proposed. The dissertation compares these methods with traditional ones, and points out that such method has effective clutter suppression, while computation is larger.
4、An estimation method for moving targets’velocities based on the combination of DPCA and DCFT is studied. The moving targets’Doppler parameters can be estimated with DCFT which is based on energy entropy. Then according to the relationship between these parameters and moving target’s velocities, the range velocity and azimuth velocity can be estimated.
5、Phase separation in InSAR with hybrid baseline is studied. In order to obtain elevation and velocities at the same time, we can tilt the baseline, then measure elevation and velocities by separating the hybrid phase. The dissertation derives the theoretical model and verifies the feasibility of this method through a simulation on the computer, then points out that in such case, moving targets can be detected firstly by methods based on the covariance matrix, then the phase can separated.
引文
[1] PAUL A.ROSEN, SCOTT HENSLEY, IAN R.JOUGHIN, FUK K.LI, SOREN N.MADSEN, ERNESTO RODRíGUEZ, AND RICHARD M.GOLDSTEIN. Synthetic Aperture Radar Interferometry. Proceeding of IEEE, Vol.88, No.3, March 2000, pp333-382.
[2]穆冬.干涉合成孔径雷达成像技术研究.南京航空航天大学博士学位论文,2001.
[3]王超,张红,刘智.星载合成孔径雷达干涉测量.科学出版社,2002.
[4]皮亦鸣,杨建宇,付毓生,杨晓波.合成孔径雷达成像原理.电子科技大学出版社,2007.
[5]魏钟铨.合成孔径雷达卫星.科学出版社,2001.
[6]袁孝康.星载合成孔径雷达导论.国防工业出版社,2003.
[7]刘永坦.雷达成像技术.哈尔滨工业大学出版社,1999. 10.
[8]保铮,邢孟道,王彤.雷达成像技术.电子工业出版社,2005.04.
[9]赵洪冰.机载合成孔径雷达运动目标检测方法研究.电子科技大学硕士学位论文,2007.
[10]郑明洁.合成孔径雷达动目标检测和成像研究.中国科学院电子学研究所博士学位论文,2003.
[11]郭锐.基于特征分解的SAR动目标检测方法.电子科技大学硕士学位论文,2007.
[12]秦放.分布式卫星系统动目标检测及混合基线相位分离方法研究.电子科技大学硕士学位论文,2007.
[13]董敏.分布式星载SAR系统的DPCA动目标检测技术研究.电子科技大学硕士学位论文,2006.
[14] SUN Long, ZHANG Changyao, HU Maolin. Performance analysis and data processing of the airborne X-band InSAR system. Asian and Pacific Conference on Synthetic Aperture Radar, November 2007, pp541-545.
[15]陶鹍.干涉合成孔径雷达数据处理及仿真研究.中国科学院电子学研究所博士学位论文,2003.
[16] Zhenfang Li, Zheng Bao, Hai Li, and Guisheng Liao. Image Autocoregistration and InSAR Interferogram Estimation Using Joint Subspace Projection. IEEE transactions on geoscience and remote sensing, VOL.44, NO.2, February 2006, pp288-297.
[17]李海,李真芳,廖桂生,保铮. InSAR干涉相位图生成的图像配准自补偿方法.中国科学,E辑,信息科学,2006,36(2):191-201.
[18]李海,廖桂生. InSAR自适应图像配准的干涉相位估计方法.电子学报,2007年3月,Vol.35,No.3,pp420-425.
[19]李海,廖桂生.基于广义导向矢量模型的InSAR干涉相位估计方法.自然科学进展, 2007年11月,Vol.17, No.11,pp1555-1564.
[20]毛志杰,廖桂生.基于联合像素模型的InSAR干涉相位稳健性估计.系统工程与电子技术,2008年1月,Vol.30,No.1,pp6-9.
[21]张晓玲.干涉合成孔径雷达成像处理技术研究.电子科技大学博士学位论文,1999.
[22]康雪艳,杨汝良.利用DPCA方法对机载单天线SAR实际数据进行动目标检测.遥感技术与应用,2004年6月,Vol.19,No.3,pp182-185.
[23]郑明洁,杨汝良.一种改进的DPCA运动目标检测方法.电子学报,2004年9月,Vol.32,No.9,pp1429-1432.
[24]郑明洁,杨汝良.基于DPCA和干涉技术的SAR动目标检测.电子与信息学报,2003年11月,Vol.25,No.11,pp1525-1530.
[25]康雪艳,杨汝良.对机载单天线SAR实际数据进行ATI动目标检测的新方法.电子学报,2005年3月,Vol.33,No.3,pp416-418.
[26]郑明洁,杨汝良.双通道沿迹干涉SAR地面动目标检测.电子与信息学报,2005年10月,Vol.27,No.10,pp1560-1563.
[27] I.C.Sikaneta,J.-Y.Chouinard. Eigendecomposition of the multi-channel covariance matrix with applications to SAR-GMTI. Elsevier Computer Science ,Signal Processing 84 (2004) , pp1501-1535.
[28] Ishuwa Sikaneta, Christoph Gierull. Ground Moving Target Detection for Along-Track Interferometric SAR Data. IEEE Aerospace Conference Proceedings,2004, pp2227-2235.
[29] I Sikaneta,C Gierull, J Y Chouinard. Metrics for SAR-GMTI based on eigen-decomposition of the sample covariance matrix[A]. Radar Conference 2003[C]. America:IEEE Press,2003,pp442-447.
[30] Saralees Nadarajah. Comments on“Eigendecomposition of the multi-channel covariance matrix with applications to SAR-GMTI”. Elsevier ScienceDirect,Signal Processing 87 (2007) , pp1534-1536.
[31]高飞,毛士艺,袁运能,玉振明.一种在双通道SAR图像域实现地面运动目标检测的方法.电子学报,2006年4月,Vol.34,No.4,pp755-760.
[32]黄廷祝,钟守铭,李正良.矩阵理论.高等教育出版社,2003.
[33]邓彦.机载双基地SAR成像算法及相关技术研究.电子科技大学硕士学位论文,2006.
[34] Xiang-Gen Xia. Discrete Chirp_Fourier Transform and Its Application to Chirp Rate Estimation.IEEE Transactions on signal processing, Vol.48, No.11, November 2000, pp3122-3133.
[35]孙泓波,郭欣,顾红,苏卫民,刘国岁.修正离散Chirp-Fourier变换及其在SAR运动目标检测中的应用.电子学报,2003年1月,Vol.31,No.1,pp25-28.
[36] Wang Yinbo, Zhang Xiaoling, Gong Zhenqiang, Tian Zhong. Comparison of Doppler frequency rate estimators in bistatic airborne SAR and experimental results. Asian and Pacific Conference on Synthetic Aperture Radar, November 2007, pp98-102.
[37]曾斌.分布式卫星SAR慢动目标检测及关键技术研究.电子科技大学博士学位论文,2006
[38]李真芳,王彤,保铮,廖桂生.同时地形高程测量和地面运动目标检测的分布式InSAR最优编队构型.宇航学报,2004年11月,Vol.25,No.6,pp642-648.
[39] Robert Siegmund, Mingquan Bao, Susanne Lehner, and Roberto Mayerle. First demonstration of surface currents imaged by hybrid along- and cross-track interferometric SAR. IEEE transactions on geoscience and remote sensing, Vol.42, No.3, March 2004, pp511-519.
[40]徐华平,周荫清,李春升.分布式小卫星合成孔径雷达多基线干涉技术.遥感遥测,2005年11月,pp23-27.
[41] Zhenfang Li, Zheng Bao, Zhiyong Suo. A Joint Image Coregistration, Phase Noise Suppression, and Phase Unwrapping Method Based On Subspace Projection for Multibaseline InSAR Systems. IEEE transactions on geoscience and remote sensing, Vol.45, No.3, March 2007, pp584-591.
[42] Gianfranco Fornaro, Fabrizio Lombardini, and Francesco Serafino. Three-Dimensional Multipass SAR Focusing: Experiments With Long-Term Spaceborne Data. IEEE transactions on geoscience and remote sensing, Vol.43, No.4, April 2004, pp702-714.
[2]穆冬.干涉合成孔径雷达成像技术研究.南京航空航天大学博士学位论文,2001.
[3]王超,张红,刘智.星载合成孔径雷达干涉测量.科学出版社,2002.
[4]皮亦鸣,杨建宇,付毓生,杨晓波.合成孔径雷达成像原理.电子科技大学出版社,2007.
[5]魏钟铨.合成孔径雷达卫星.科学出版社,2001.
[6]袁孝康.星载合成孔径雷达导论.国防工业出版社,2003.
[7]刘永坦.雷达成像技术.哈尔滨工业大学出版社,1999. 10.
[8]保铮,邢孟道,王彤.雷达成像技术.电子工业出版社,2005.04.
[9]赵洪冰.机载合成孔径雷达运动目标检测方法研究.电子科技大学硕士学位论文,2007.
[10]郑明洁.合成孔径雷达动目标检测和成像研究.中国科学院电子学研究所博士学位论文,2003.
[11]郭锐.基于特征分解的SAR动目标检测方法.电子科技大学硕士学位论文,2007.
[12]秦放.分布式卫星系统动目标检测及混合基线相位分离方法研究.电子科技大学硕士学位论文,2007.
[13]董敏.分布式星载SAR系统的DPCA动目标检测技术研究.电子科技大学硕士学位论文,2006.
[14] SUN Long, ZHANG Changyao, HU Maolin. Performance analysis and data processing of the airborne X-band InSAR system. Asian and Pacific Conference on Synthetic Aperture Radar, November 2007, pp541-545.
[15]陶鹍.干涉合成孔径雷达数据处理及仿真研究.中国科学院电子学研究所博士学位论文,2003.
[16] Zhenfang Li, Zheng Bao, Hai Li, and Guisheng Liao. Image Autocoregistration and InSAR Interferogram Estimation Using Joint Subspace Projection. IEEE transactions on geoscience and remote sensing, VOL.44, NO.2, February 2006, pp288-297.
[17]李海,李真芳,廖桂生,保铮. InSAR干涉相位图生成的图像配准自补偿方法.中国科学,E辑,信息科学,2006,36(2):191-201.
[18]李海,廖桂生. InSAR自适应图像配准的干涉相位估计方法.电子学报,2007年3月,Vol.35,No.3,pp420-425.
[19]李海,廖桂生.基于广义导向矢量模型的InSAR干涉相位估计方法.自然科学进展, 2007年11月,Vol.17, No.11,pp1555-1564.
[20]毛志杰,廖桂生.基于联合像素模型的InSAR干涉相位稳健性估计.系统工程与电子技术,2008年1月,Vol.30,No.1,pp6-9.
[21]张晓玲.干涉合成孔径雷达成像处理技术研究.电子科技大学博士学位论文,1999.
[22]康雪艳,杨汝良.利用DPCA方法对机载单天线SAR实际数据进行动目标检测.遥感技术与应用,2004年6月,Vol.19,No.3,pp182-185.
[23]郑明洁,杨汝良.一种改进的DPCA运动目标检测方法.电子学报,2004年9月,Vol.32,No.9,pp1429-1432.
[24]郑明洁,杨汝良.基于DPCA和干涉技术的SAR动目标检测.电子与信息学报,2003年11月,Vol.25,No.11,pp1525-1530.
[25]康雪艳,杨汝良.对机载单天线SAR实际数据进行ATI动目标检测的新方法.电子学报,2005年3月,Vol.33,No.3,pp416-418.
[26]郑明洁,杨汝良.双通道沿迹干涉SAR地面动目标检测.电子与信息学报,2005年10月,Vol.27,No.10,pp1560-1563.
[27] I.C.Sikaneta,J.-Y.Chouinard. Eigendecomposition of the multi-channel covariance matrix with applications to SAR-GMTI. Elsevier Computer Science ,Signal Processing 84 (2004) , pp1501-1535.
[28] Ishuwa Sikaneta, Christoph Gierull. Ground Moving Target Detection for Along-Track Interferometric SAR Data. IEEE Aerospace Conference Proceedings,2004, pp2227-2235.
[29] I Sikaneta,C Gierull, J Y Chouinard. Metrics for SAR-GMTI based on eigen-decomposition of the sample covariance matrix[A]. Radar Conference 2003[C]. America:IEEE Press,2003,pp442-447.
[30] Saralees Nadarajah. Comments on“Eigendecomposition of the multi-channel covariance matrix with applications to SAR-GMTI”. Elsevier ScienceDirect,Signal Processing 87 (2007) , pp1534-1536.
[31]高飞,毛士艺,袁运能,玉振明.一种在双通道SAR图像域实现地面运动目标检测的方法.电子学报,2006年4月,Vol.34,No.4,pp755-760.
[32]黄廷祝,钟守铭,李正良.矩阵理论.高等教育出版社,2003.
[33]邓彦.机载双基地SAR成像算法及相关技术研究.电子科技大学硕士学位论文,2006.
[34] Xiang-Gen Xia. Discrete Chirp_Fourier Transform and Its Application to Chirp Rate Estimation.IEEE Transactions on signal processing, Vol.48, No.11, November 2000, pp3122-3133.
[35]孙泓波,郭欣,顾红,苏卫民,刘国岁.修正离散Chirp-Fourier变换及其在SAR运动目标检测中的应用.电子学报,2003年1月,Vol.31,No.1,pp25-28.
[36] Wang Yinbo, Zhang Xiaoling, Gong Zhenqiang, Tian Zhong. Comparison of Doppler frequency rate estimators in bistatic airborne SAR and experimental results. Asian and Pacific Conference on Synthetic Aperture Radar, November 2007, pp98-102.
[37]曾斌.分布式卫星SAR慢动目标检测及关键技术研究.电子科技大学博士学位论文,2006
[38]李真芳,王彤,保铮,廖桂生.同时地形高程测量和地面运动目标检测的分布式InSAR最优编队构型.宇航学报,2004年11月,Vol.25,No.6,pp642-648.
[39] Robert Siegmund, Mingquan Bao, Susanne Lehner, and Roberto Mayerle. First demonstration of surface currents imaged by hybrid along- and cross-track interferometric SAR. IEEE transactions on geoscience and remote sensing, Vol.42, No.3, March 2004, pp511-519.
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