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Wavelet-based L_(1/2) regularization for CS-TomoSAR imaging of forested area

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Journal of Systems Engineering and Electronics 2020年第6期31卷 1160-1166页

作者： BI Hui CHENG Yuan zhu daiyin HONG Wen College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China

Tomographic synthetic aperture radar(TomoSAR)imaging exploits the antenna array measurements taken at different elevation aperture to recover the reflectivity function along the elevation *** these years,for the sparse elevation distribution,compressive sensing(CS)is a developed favorable technique for the high-resolution elevation reconstruction in TomoSAR by solving an L_(1) regularization ***,because the elevation distribution in the forested area is nonsparse,if we want to use CS in the recovery,some basis,such as wavelet,should be exploited in the sparse L_(1/2) representation of the elevation reflectivity *** paper presents a novel wavelet-based L_(2) regularization CS-TomoSAR imaging method of the forested *** the proposed method,we first construct a wavelet basis,which can sparsely represent the elevation reflectivity function of the forested area,and then reconstruct the elevation distribution by using the L_(1/2) regularization *** to the wavelet-based L_(1) regularization TomoSAR imaging,the proposed method can improve the elevation recovered quality efficiently.

关键词： tomographic synthetic aperture radar(TomoSAR) compressive sensing(CS) L_(1/2)regularization wavelet basis

Wind turbine clutter mitigation using morphological component analysis with group sparsity

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Journal of Systems Engineering and Electronics 2023年第3期34卷 714-722页

作者： WAN Xiaoyu SHEN Mingwei WU Di zhu daiyin College of Computer and Information Hohai UniversityNanjing 211100China Key Laboratory of Radar Imaging and Microwave Photonics&Ministry of Education Nanjing University of Aeronautics and AstronauticsNanjing 210016China

To address the problem that dynamic wind turbine clutter(WTC)significantly degrades the performance of weather radar,a WTC mitigation algorithm using morphological component analysis(MCA)with group sparsity is studied in this *** ground clutter is suppressed firstly to reduce the morphological compositions of radar *** that,the MCA algorithm is applied and the window used in the short-time Fourier transform(STFT)is optimized to lessen the spectrum leakage of ***,the group sparsity structure of WTC in the STFT domain can be utilized to decrease the degrees of freedom in the solution,thus contributing to better estimation performance of weather *** effectiveness and feasibility of the proposed method are demonstrated by numerical simulations.

关键词： weather radar wind turbine clutter(WTC) morphological component analysis(MCA) short-time Fourier transform(STFT) group sparsity

IMAGE-BASED SCALING FOR SHIP TOP VIEW ISAR IMAGES

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Journal of Electronics(China) 2008年第1期25卷 76-83页

作者： Wang Ling zhu daiyin zhu Zhaoda College of Information Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A high quality top view or side view ship ISAR image with proper cross-range scale is very useful for target recognition. A technique aiming at solving the ship top view image scaling is developed, in which the cross-range scale information is obtained by measuring the slopes of the two feature lines of the ship, the centerline and the stern line. Neither the prior knowledge about the ship nor the tracking data is required. The proposed technique is fully based on the image. It is used with ease and high efficiency. Examples are provided to demonstrate its effectiveness with both simulated and real data. The scaled results are in accordance with the real shape of the ship.

关键词： Inverse Synthetic Aperture Radar (ISAR) Ship Scaling Recognition

AN IMPROVED SAR-GMTI METHOD BASED ON EIGEN-DECOMPOSITION OF THE SAMPLE COVARIANCE MATRIX

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Journal of Electronics(China) 2010年第3期27卷 382-390页

作者： Tian Bin zhu daiyin zhu Zhaoda College of Information Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

An improved two-channel Synthetic Aperture Radar Ground Moving Target Indication (SAR-GMTI) method based on eigen-decomposition of the covariance matrix is investigated. Based on the joint Probability Density Function (PDF) of the Along-Track Interferometric (ATI) phase and the similarity between the two SAR complex images, a novel ellipse detector is presented and is applied to the indication of ground moving targets. We derive its statistics and analyze the performance of detection process in detail. Compared with the approach using the ATI phase, the ellipse detector has a better performance of detection in homogenous clutter. Numerical experiments on simulated data are presented to validate the improved performance of the ellipse detector with respect to the ATI phase approach. Finally, the detection capability of the proposed method is demonstrated by measured SAR data.

关键词： Ground moving target indication Sample covariance matrix Eigen-decomposition Ellipse detector

RESEARCH ON THE BISTATIC FORWARD-LOOKING SAR IMAGING

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Journal of Electronics(China) 2010年第6期27卷 735-741页

作者： Wang Xin zhu daiyin zhu Zhaoda （ Nanjing University of Aeronautics ＆ Astronautics Nanjing 210016 China）

The bistatic Synthetic Aperture Radar (SAR) systems with separate transmitter and receiver antennas provide a new potential to imaging in the forward-looking geometry. Analysis of the Doppler property in this paper indicates the feasibility of Bistatic Forward-Looking (BFL) SAR imaging. Considering the different Doppler property determined by the two platforms in BFL SAR, a new 2-D point target spectrum is derived in our study. Based on the spectrum, an imaging method is chosen for the configuration, and the point target simulation validates the analysis.

关键词： Synthetic Aperture Radar (SAR) Bistatic Forward-Looking (BFL) Range Doppler Algorithm (RDA)

Dynamic Behavior of Optical Soliton Interactions in Optical Communication Systems

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Chinese Physics Letters 2022年第11期39卷 28-32页

作者： Shubin Wang Guoli Ma Xin Zhang daiyin zhu College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China Flight College Binzhou UniversityBinzhou 256603China Institute of Aeronautical Engineering Binzhou UniversityBinzhou 256603China

In optical systems,it is necessary to investigate the propagation of optical solitons in optical fiber systems for fiber-optic *** means of the bilinear method,we obtain the two-soliton solution of the variable coefficient higher-order coupled nonlinear Schrodinger *** to the obtained two-soliton solution,a novel two-soliton interaction structure of the system is constructed,and their interactions are *** optical solitons occur with elastic interaction under certain conditions,and their amplitudes,shapes and velocities remain unchanged before and after the *** addition to the elastic interaction,splitting action and polymerization also *** present study on the dynamic behavior of interaction of optical solitons may be valuable for research and applications in optical communication and other fields.

关键词： equation soliton interaction

Optimal ship imaging for shore-based ISAR using DCF estimation

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Journal of Systems Engineering and Electronics 2015年第4期26卷 739-745页

作者： Ling Wang Zhenxiao Cao Ning Li Teng Jing daiyin zhu Key Laboratory of Radar Imaging and Microwave Photonics Ministry of EducationNanjing University of Aeronautics and Astronautics Department of Space Microwave Remote Sensing System Institute of Electronics Chinese Academy of Sciences

The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar （ISAR） in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and optimal imaging duration. A novel method for optimal imaging instants selection based on the estimation of the Doppler centroid frequencies （DCFs） of a series of images obtained over continuous short durations is proposed. Combined with the optimal imaging duration selection scheme using the image contrast maximization criteria, this method can provide the ship images with the highest focus. Simulated and real data pro- cessing results verify the effectiveness of the proposed imaging method.

关键词： inverse synthetic aperture radar (ISAR) ship target,optimal imaging time selection Doppler centroid frequency (DCF).

NEW RANGE ALIGNMENT ALGORITHM FOR ISAR BASED ON HIGH ORDER MOMENT

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Journal of Electronics(China) 2007年第4期24卷 509-514页

作者： Wang Ling zhu daiyin zhu Zhaoda College of Information Science and Technology Nanjing University of Aeronautics and Astronautics. Nanjing 210015 China

A new technique is proposed for range alignment in Inverse Synthetic Aperture Radar （ISAR）. The basic idea is to perform range alignment using a maximum kurtosis （fourth-order central moment） criterion. After maximizing the kurtosis of the combined range profile of two adjacent echoes, the amount of range shift between them can be automatically tracked out. The combined range profile is constructed by a max operation, which only reserves the larger elements of the two echoes, and the echoes＇ amplitudes are limited before they are combined. This algorithm has bee~ used to process real ISAR data and the results demonstrate the effectiveness of the method. Compared with the correlation method and the minimum entropy method, the proposed algorithm obtains much better results in both examples in this paper. Its computation complexity has the same order of magnitude as the minimum entropy method.

关键词： Inverse Synthetic Aperture Radar (ISAR) Range alignment High order moment Kutosis

An improved iterative thresholding algorithm for L1-norm regularization based sparse SAR imaging

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Science China(Information Sciences) 2020年第11期63卷 330-339页

作者： Hui BI Yong LI daiyin zhu Guoan BI Bingchen ZHANG Wen HONG Yirong WU College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Key Laboratory of Radar Imaging and Microwave Photonics Ministry of Education Nanjing University of Aeronautics and Astronautics School of Electrical and Electronic Engineering Nanyang Technological University Aerospace Information Research Institute Chinese Academy of Sciences

Dear editor,Sparse signal processing techniques have been widely used after being introduced to synthetic aperture radar (SAR) imaging, and have shown desirable potential in imaging performance improvement compared wi... 详细信息

关键词： Synthetic aperture radar Sparse microwave imaging SAR imaging Radar imaging Sparse signal processing