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Micro-motion effect in inverse synthetic aperture radar imaging of ballistic mid-course targets 被引量:4
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作者 邹飞 付耀文 姜卫东 《Journal of Central South University》 SCIE EI CAS 2012年第6期1548-1557,共10页
For ballistic mid-course targets,in addition to constant orbital motion,the target or any structure on the target undergoes micro-motion dynamics,such as spin,precession and tumbling.The micro-motion characteristics o... For ballistic mid-course targets,in addition to constant orbital motion,the target or any structure on the target undergoes micro-motion dynamics,such as spin,precession and tumbling.The micro-motion characteristics of the ballistic mid-course targets were discussed.The target motion model and inverse synthetic aperture radar(ISAR) imaging model for this kind of targets were built.Then,the influence of micro-motion on ISAR imaging based on the established imaging model was presented.The computer simulation to get mid-course target echoes from static darkroom electromagnetic scattering data based on the established target motion model was realized.The imaging results of computer simulation show the validity of ISAR imaging analysis for micro-motion targets. 展开更多
关键词 MICRO-MOTION ballistic mid-course targets inverse synthetic aperture radar imaging (ISAR)
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Inverse synthetic aperture radar range profile compensation of plasma-sheath-enveloped reentry object
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作者 Yaocong XIE Xiaoping LI +3 位作者 Fangfang SHEN Bowen BAI Lei SHI Xuyang CHEN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2022年第7期148-161,共14页
The scattering points in a plasma sheath characterized with coupled velocities can cause pulse compression mismatching,which results in displacement and energy diffusion in the onedimension range profile.To solve this... The scattering points in a plasma sheath characterized with coupled velocities can cause pulse compression mismatching,which results in displacement and energy diffusion in the onedimension range profile.To solve this problem,we deduce the echo model of the plasma-sheathenveloped reentry object.By estimating the coupled velocities,we propose a compensation method to correct the defocus of an inverse synthetic aperture radar(ISAR)image in range dimension to improve the quality of the ISAR images.The simulation results suggest that the echoes from different regions of the surface of the reentry object have various coupling velocities,and the higher the coupled velocity,the more serious the displacement and energy diffusion in the range dimension.Our proposed method can correct the range dimension aberration.Two measurement metrics were used to evaluate the improvement of the compensation method. 展开更多
关键词 plasma sheath inverse synthetic aperture radar imaging DEFOCUS coupled velocity reentry object
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A modified OMP method for multi-orbit three dimensional ISAR imaging of the space target
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作者 JIANG Libing ZHENG Shuyu +2 位作者 YANG Qingwei YANG Peng WANG Zhuang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第4期879-893,共15页
The conventional two dimensional(2D)inverse synthetic aperture radar(ISAR)imaging fails to provide the targets'three dimensional(3D)information.In this paper,a 3D ISAR imaging method for the space target is propos... The conventional two dimensional(2D)inverse synthetic aperture radar(ISAR)imaging fails to provide the targets'three dimensional(3D)information.In this paper,a 3D ISAR imaging method for the space target is proposed based on mutliorbit observation data and an improved orthogonal matching pursuit(OMP)algorithm.Firstly,the 3D scattered field data is converted into a set of 2D matrix by stacking slices of the 3D data along the elevation direction dimension.Then,an improved OMP algorithm is applied to recover the space target's amplitude information via the 2D matrix data.Finally,scattering centers can be reconstructed with specific three dimensional locations.Numerical simulations are provided to demonstrate the effectiveness and superiority of the proposed 3D imaging method. 展开更多
关键词 three dimensional inverse synthetic aperture radar(3D ISAR)imaging space target improved orthogonal matching pursuit(OMP)algorithm scattering centers
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Entropy function optimization for radar imaging
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作者 邱晓晖 陈昊 《Journal of Southeast University(English Edition)》 EI CAS 2009年第4期427-430,共4页
The convergence performance of the minimum entropy auto-focusing(MEA) algorithm for inverse synthetic aperture radar(ISAR) imaging is analyzed by simulation. The results show that a local optimal solution problem ... The convergence performance of the minimum entropy auto-focusing(MEA) algorithm for inverse synthetic aperture radar(ISAR) imaging is analyzed by simulation. The results show that a local optimal solution problem exists in the MEA algorithm. The cost function of the MEA algorithm is not a downward-convex function of multidimensional phases to be compensated. Only when the initial values of the compensated phases are chosen to be near the global minimal point of the entropy function, the MEA algorithm can converge to a global optimal solution. To study the optimal solution problem of the MEA algorithm, a new scheme of entropy function optimization for radar imaging is presented. First, the initial values of the compensated phases are estimated by using the modified Doppler centroid tracking (DCT)algorithm. Since these values are obtained according to the maximum likelihood (ML) principle, the initial phases can be located near the optimal solution values. Then, a fast MEA algorithm is used for the local searching process and the global optimal solution can be obtained. The simulation results show that this scheme can realize the global optimization of the MEA algorithm and can avoid the selection and adjustment of parameters such as iteration step lengths, threshold values, etc. 展开更多
关键词 radar signal processing inverse synthetic aperture radar(ISAR) imaging AUTO-FOCUSING
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Compressive Sensing Inverse Synthetic Aperture Radar Imaging Based on Gini Index Regularization 被引量:2
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作者 Can Feng Liang Xiao Zhi-Hui Wei 《International Journal of Automation and computing》 EI CSCD 2014年第4期441-448,共8页
In compressive sensing(CS) based inverse synthetic aperture radar(ISAR) imaging approaches, the quality of final image significantly depends on the number of measurements and the noise level. In this paper, we propose... In compressive sensing(CS) based inverse synthetic aperture radar(ISAR) imaging approaches, the quality of final image significantly depends on the number of measurements and the noise level. In this paper, we propose an improved version of CSbased method for inverse synthetic aperture radar(ISAR) imaging. Different from the traditional l1 norm based CS ISAR imaging method, our method explores the use of Gini index to measure the sparsity of ISAR images to improve the imaging quality. Instead of simultaneous perturbation stochastic approximation(SPSA), we use weighted l1 norm as the surrogate functional and successfully develop an iteratively re-weighted algorithm to reconstruct ISAR images from compressed echo samples. Experimental results show that our approach significantly reduces the number of measurements needed for exact reconstruction and effectively suppresses the noise. Both the peak sidelobe ratio(PSLR) and the reconstruction relative error(RE) indicate that the proposed method outperforms the l1 norm based method. 展开更多
关键词 Compressive sensing inverse synthetic aperture radar (ISAR) imaging SPARSITY Gini index REGULARIZATION
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Fast ISAR imaging method based on scene segmentation 被引量:1
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作者 Mingjiu Lü Shaodong Li +2 位作者 Wenfeng Chen Jun Yang Xiaoyan Ma 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第6期1078-1088,共11页
Although compressed sensing inverse synthetic aperture radar(ISAR) imaging methods are widely used in radar signal processing, its reconstructing time and memory storage space requirements are very high. The main reas... Although compressed sensing inverse synthetic aperture radar(ISAR) imaging methods are widely used in radar signal processing, its reconstructing time and memory storage space requirements are very high. The main reason is that large scene reconstruction needs a higher dimension of the sensing matrix. To reduce this limitation, a fast high resolution ISAR imaging method,which is based on scene segmentation for random chirp frequencystepped signals, is proposed. The idea of scene segmentation is used to solve the problems aforementioned. In the method,firstly, the observed scene is divided into multiple sub-scenes and then the sub-scenes are reconstructed respectively. Secondly, the whole image scene can be obtained through the stitching of the sub-scenes. Due to the reduction of the dimension of the sensing matrix, the requirement of the memory storage space is reduced substantially. In addition, due to the nonlinear superposition of the reconstructed time of the segmented sub-scenes, the reconstruction time is reduced, and the purpose of fast imaging is achieved.Meanwhile, the feasibility and the related factors which affect the performance of the proposed method are also analyzed, and the selection criterion of the scene segmentation is afforded. Finally,theoretical analysis and simulation results demonstrate the feasibility and effectiveness of the proposed method. 展开更多
关键词 compressed sensing(CS) inverse synthetic aperture radar(ISAR) imaging random chirp frequency-stepped signal scene segmentation
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Automatic target recognition method for inverse synthetic aperture sonar imaging 被引量:2
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作者 ZHU Zhaotong PENG Shibao +1 位作者 XU Jia XU Xiaomei 《Chinese Journal of Acoustics》 CSCD 2018年第4期463-476,共14页
To address the randomness of target aspect angle and the incompleteness of observed target in inverse synthetic aperture sonar(ISAS) imaging,a method for target recognition is proposed based on topology vector feat... To address the randomness of target aspect angle and the incompleteness of observed target in inverse synthetic aperture sonar(ISAS) imaging,a method for target recognition is proposed based on topology vector feature(TVF) of multiple highlights. Analysis of the projection relationship from 3 D space to 2 D imaging plane in ISAS indicates that the distance between two highlights in the cross-range scale calibrated image is determined by the distance between the corresponding physical scattering centers. Then, TVFs of different targets, which remain stable in various possibilities of target aspect angle, can be built. K-means clustering technique is used to effectively alleviate effect of the point missing due to incompleteness of the observed target. A nearest neighbor classifier is used to realize the target recognition. The ISAS experimental results using underwater scaled models are provided to demonstrate the effectiveness of the proposed method. A classification rate of 84.0% is reached. 展开更多
关键词 Automatic target recognition method for inverse synthetic aperture sonar imaging
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ISAR cross-range scaling based on the MUSIC technique 被引量:3
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作者 LIU Qiuchen WANG Yong ZHANG Qingxiang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第5期928-938,共11页
Cross-range scaling plays an important role in the inverse synthetic aperture radar(ISAR) imaging. Many of the published cross-range scaling algorithms are based on the fast Fourier transformation(FFT). However, the F... Cross-range scaling plays an important role in the inverse synthetic aperture radar(ISAR) imaging. Many of the published cross-range scaling algorithms are based on the fast Fourier transformation(FFT). However, the FFT technique is resolution limited, so that the FFT-based algorithms will fail in the rotation velocity(RV) estimation of the slow rotation target. In this paper,we propose an accurate cross-range scaling algorithm based on the multiple signal classification(MUSIC) method. We first select some range bins with the mono-component linear frequency modulated(LFM) signal model. Then, we dechirp the signal of each selected range bin into the form of sinusoidal signal, and utilize the super-resolution MUSIC technique to accurately estimate the frequency. After processing all the range bins, a linear relationship related to the RV can be obtained. Eventually, the ISAR image can be scaled. The proposal can precisely estimate the small RV of the slow rotation target with low computational complexity. Furthermore, the proposal can also be used in the case of cross-range scaling for the sparse aperture data. Experimental results with the simulated and raw data validate the superiority of the novel method. 展开更多
关键词 inverse synthetic aperture radar(ISAR)imaging cross-range scaling multiple signal classification(MUSIC)method slow rotation target sparse aperture
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Simultaneous ISAR imaging of group targets flying in formation
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作者 Chen Jie Xiao Huaitie +1 位作者 Song Zhiyong Fan Hongqi 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2014年第6期1554-1561,共8页
This paper proposes a novel inverse synthetic aperture radar(ISAR) imaging method based on second-order keystone transform(KT) and Sandglass transform for group targets flying in a formation with constant accelera... This paper proposes a novel inverse synthetic aperture radar(ISAR) imaging method based on second-order keystone transform(KT) and Sandglass transform for group targets flying in a formation with constant accelerated rectilinear motion in the same radar beam. First, range curvature and range walk of each sub-target among group targets are corrected by the second-order KT combined with the quadratic phase term compensation. After range alignment, the signals in each range frequency cell can be modelled as multiple chirp signals and then the Sandglass transform is utilized to cross-range imaging, which transforms the time–frequency distribution of the signals in each range frequency cell into beelines parallel to the slow time axis simultaneously. Finally, cross-range profiles of group targets in each range frequency cell are obtained via a projection of the perk of every scatterer in the two-dimensional accumulation plane onto the frequency axis. The advantage of the proposed method is that it can align range profiles of each sub-target simultaneously and image cross-range profiles directly without separating the returned signals, which simplifies the operation procedure. Simulation results are used to demonstrate the effectiveness of the proposed method. 展开更多
关键词 Formation flying Group targets inverse synthetic aperture radar Keystone transform Radar imaging Sandglass transform
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