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A SAR sidelobe suppression algorithm based on modified spatially variant apodization

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Science china(Technological sciences) 2010年第9期53卷 2542-2551页

作者： NI Chong1,2,WANG YanFei1,XU XiangHui1,ZHOU ChangYi1 & CUI PengFei1,2 1 institute of electronics,chinese academy of sciences,beijing 100190,china 2 Graduate University of chinese academy of sciences,beijing 100039,china institute of electronics Chinese Academy of Sciences Graduate University of chinese academy of sciences

The existing spatially variant apodizations (SVAs) either cannot depress the sidelobes effectively or reduce the energy of the *** improve this,a modified SVA (MSVA) is put forward in this paper,which expands the traditional filter from 3-taps to 5-taps and sets relevant parameters according to different sampling rates to get the excellent result that satisfies constrained optimization theory.A method for synthetic aperture radar (SAR) sidelobe control based on MSVA is presented,which applies MSVA to range compression and azimuth compression to control *** method which is available for any Nyquist sampling rate can both depress the sidelobes effectively and keep the energy of the mainlobe and the resolution of the *** method can reduce sidelobe levels more effectively than classical amplitude weighting while maintaining the image resolution,as demonstrated by the result of the experiment.

关键词： synthetic aperture radar sidelobe suppression resolution SVA

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Synthetic aperture radar tomography sampling criteria and three-dimensional range migration algorithm with elevation digital spotlighting

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Science in china(Series F) 2009年第1期52卷 100-114页

作者： TAN WeiXian1,2,3?, HONG Wen1,2, WANG YanPing1,2, LIN Yun1,2,3 & WU YiRong1,2 1 State Key Laboratory of Microwave Imaging Technology, beijing 100190, china 2 institute of electronics, chinese academy of sciences, beijing 100190, china 3 Graduate School, chinese academy of sciences, beijing 100190, china State Key Laboratory of Microwave Imaging Technology institute of electronics Chinese Academy of Sciences Graduate School Chinese Academy of Sciences

Based on the general geometric model of multi-baseline Synthetic Aperture Radar Tomography （TomoSAR）, the three-dimensional （3-D） sampling criteria, the analytic expression of the 3-D Point Spread Function （PSF） and the 3-D resolution are derived in the 3-D wavenumber domain in this paper. Considering the relationship between the observation geometry and the size of illuminated scenario, a 3-D Range Migration Algorithm with Elevation Digital Spotlighting （RMA-EDS） is proposed. With this algorithm 3-D images of the area of interest can be directly and accurately reconstructed in the 3-D space avoiding the complex operations of 3-D geometric correction. Finally, theoretical analyses and simulation results are presented to demonstrate the shift-varying property of the 3-D PSF and the spatialvarying property of the 3-D resolution and to demonstrate the validity of the 3-D RMA-EDS.

关键词： synthetic aperture radar tomography (TomoSAR) three-dimensional (3-D) SAR imaging 3-D sampling criteria 3-D resolution,3-D range migration algorithm with elevation digital spotlighting (RMA-EDS)

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An improved imaging algorithm for fixed-receiver bistatic SAR

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Science china(Information sciences) 2010年第7期53卷 1461-1469页

作者： GENG XuPu1,2,3, HU YingHui1,2, YAN HongHui2 & WANG YanFei2 1Graduate School of the chinese academy of sciences, beijing 100039, china 2institute of electronics, chinese academy of sciences, beijing 100190, china 3beijing institute of Environment Features, beijing 100854, china Graduate School of the chinese academy of sciences institute of electronics Chinese Academy of Sciences beijing institute of Environment Features

Based on the signal model of fixed-receiver bistatic SAR, this paper analyzes the characteristics of azimuth-variant, which includes variation of range migration curve and variation of Doppler rate caused by different azimuth position of targets. Then, an extended nonlinear chirp scaling (NLCS) algorithm is proposed, with its flowchart and phase compensation functions being provided. Simulation results show that the algorithm is available for the characteristics of azimuth-variant of fixed-receiver bistatic SAR, and good focused radar images could be acquired.

关键词： synthetic aperture radar (SAR) bistatic SAR fixed-receiver characteristics of azimuth-variant range cell migration correction (RCMC)

Sparse microwave imaging:Principles and applications

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Science china(Information sciences) 2012年第8期55卷 1722-1754页

作者： ZHANG BingChen1,2,HONG Wen1,2 & WU YiRong1,2 1Science and Technology on Microwave Imaging Laboratory,beijing 100190,china 2institute of electronics,chinese academy of sciences,beijing 100190,china Science and Technology on Microwave Imaging Laboratory Beijing China institute of electronics Chinese Academy of Sciences Beijing China

This paper provides principles and applications of the sparse microwave imaging theory and *** aperture radar(SAR) is an important method of modern remote *** decades microwave imaging technology has achieved remarkable progress in the system performance of microwave imaging technology,and at the same time encountered increasing complexity in system *** sparse microwave imaging introduces the sparse signal processing theory to radar imaging to obtain new theory,new system and new methodology of microwave *** on classical SAR imaging model and fundamental theories of sparse signal processing,we can derive the model of sparse microwave imaging,which is a sparse measurement and recovery problem and can be solved with various *** exist several fundamental points that must be considered in the efforts of applying sparse signal processing to radar imaging,including sparse representation,measurement matrix construction,unambiguity reconstruction and performance *** on these considerations,the sparse signal processing could be successfully applied to radar imaging,and achieve benefits in several aspects,including improvement of image quality,reduction of data amount for sparse scene and enhancement of system *** sparse signal processing has also been applied in several specific radar imaging applications.

关键词： sparse microwave imaging sparse signal processing compressive sensing synthetic aperture radar radar imaging

Influence factors of sparse microwave imaging radar system performance:approaches to waveform design and platform motion analysis

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Science china(Information sciences) 2012年第10期55卷 2301-2317页

作者： ZHANG Zhe 1,2,3,ZHANG BingChen 1,2,JIANG ChengLong 1,2,3,XIANG Yin 1,2,HONG Wen 1,2 & WU YiRong 1,2 1 Science and Technology on Microwave Imaging Laboratory,beijing 100190,china 2 institute of electronics,chinese academy of sciences,beijing 100190,china 3 Graduate University,chinese academy of sciences,beijing 100190,china Science and Technology on Microwave Imaging Laboratory Beijing China institute of electronics Chinese Academy of Sciences Beijing China Graduate University Chinese Academy of Sciences Beijing China

Sparse microwave imaging radar is a newly developed concept of microwave imaging system,which tries to combine the traditional radar imaging system with sparse signal processing theories,achieving the aim of reducing the complexity of microwave imaging systems and enhancing the system *** this paper,we introduce some basic concepts of sparse signal processing theory,and then apply it to the traditional radar imaging system to get the mathematical model of sparse microwave imaging *** analyze the factors that determine the performance of sparse microwave imaging radar,including scene,waveform and *** to the radar model,we analyze how these factors influence the radar system and how to optimize *** results of the sparse microwave imaging radar system are also provided.

关键词： sparse microwave imaging radar synthetic aperture radar compressive sensing Lq regularization waveform design

Multi-channel SAR imaging based on distributed compressive sensing

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Science china(Information sciences) 2012年第2期55卷 245-259页

作者： LIN YueGuan1,2,3,ZHANG BingChen1,2,JIANG Hai1,2,3,HONG Wen1,2 & WU YiRong1,2 1National Key Laboratory of Science and Technology on Microwave Imaging,beijing 100190,china 2institute of electronics,chinese academy of sciences,beijing 100190,china 3Graduate University of chinese academy of sciences,beijing 100049,china National Key Laboratory of Science and Technology on Microwave Imaging institute of electronics Chinese Academy of Sciences Graduate University of chinese academy of sciences

The rapid development of compressive sensing(CS)shows that it is possible to recover a sparse signal from very limited *** aperture radar(SAR)imaging based on CS can reconstruct the target scene with a reduced number of collected samples by solving an optimization *** multi-channel SAR imaging based on CS,each channel requires sufficient samples for separate imaging and the total number of samples could still be *** propose an imaging algorithm based on distributed compressive sensing(DCS)that reconstructs scenes jointly under multiple ***-channel SAR imaging based on DCS not only exploits the sparsity of the target scene,but also exploits the correlation among *** requires significantly fewer samples than multi-channel SAR imaging based on *** multiple channels offer different sampling rates,DCS joint processing can reconstruct target scenes with a much more flexible allocation of the number of measurements offered by each channel than that used in separate CS processing.

关键词： synthetic aperture radar multi-channel synthetic aperture radar compressive sensing distributed compressive sensing

A universal adaptive vector quantization algorithm for space-borne SAR raw data

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Science china(Information sciences) 2012年第6期55卷 1280-1289页

作者： QI HaiMing 1,2,HUA Bin 1,2,LI Xin 1,2,YU WeiDong 1 & HONG Wen 1,2 1 institute of electronics,chinese academy of sciences,beijing 100190,china 2 National Key Laboratory of Microwave Imaging Technology,beijing 100190,china institute of electronics Chinese Academy of Sciences National Key Laboratory of Microwave Imaging Technology

Codebook of conventional VQ cannot be generally used and needs real time onboard updating,which is hard to implement in spaceborne SAR *** order to solve this problem,this paper analyses the characteristic of space-borne SAR raw data firstly,and then utilizes the distortion function of multidimensional space as criterion,and finally the adaptive code book design algorithm is proposed according to the joint probability density function of the input ***,the feasibility of the new algorithm in cascade with entropy coding and the robustness of the algorithm when error occurs during transmission are analysed based on the encoding and decoding *** results of real data show that codebook deriving from the new algorithm can be generally used and designed off-line,which makes VQ a practical algorithm for space-borne SAR raw data compression.

关键词： synthetic aperture radar (SAR) compression raw data block adaptive quantization (BAQ) vector quantization (VQ)

Waveform design and high-resolution imaging of cognitive radar based on compressive sensing

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Science china(Information sciences) 2012年第11期55卷 2590-2603页

作者： LUO Ying1,ZHANG Qun1,HONG Wen2 & WU YiRong2 1Telecommunication Engineering institute,Air Force Engineering University,Xi'an 710077,china 2institute of electronics,chinese academy of sciences,beijing 100190,china Telecommunication Engineering institute Air Force Engineering University Xi’an China institute of electronics Chinese Academy of Sciences Beijing China

We introduce the compressive sensing(CS) theory for waveform design of cognitive radar,and then propose an algorithm for the high-resolution radar signal waveform and its corresponding imaging method based on the sparse orthogonal frequency division multiplexing-linear frequency modulation(OFDM-LFM) *** first present the principle of spectrum synthesis and high-resolution imaging based on OFDM-LFM ***,we propose the spectrum-sparse waveform design criterion and the reconstruction algorithm for a highresolution range profile(HRRP) based on *** on this,we analyze in detail the relationship between the scattering characteristics of the target and the parameters of the designed signal,and we construct the feedback of the target characteristics on the ***,the "cognitive" function of radar can be achieved by adaptively adjusting the waveform with the target *** are given to validate the effectiveness of the proposed algorithm.

关键词： cognitive radar waveform design compressive sensing radar imaging

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基于可回收能力的空间行波管高效率研究

微波学报 2010年第S1期26卷 526-529页

作者：易红霞肖刘刘濮鲲李国超薛智浩中国科学院电子学研究所北京100190 中国科学院研究生院北京100049

效率是行波管设计的重要指标之一。对于空间行波管,效率的提高可以立即转化为经济效益。本文通过对注波互作用电路参数的优化设计,得到便于收集的"作用完了"的电子注。通常具有高电子效率的电子注,能量分散较大,不利于收集。通过设定电... 详细信息

效率是行波管设计的重要指标之一。对于空间行波管,效率的提高可以立即转化为经济效益。本文通过对注波互作用电路参数的优化设计,得到便于收集的"作用完了"的电子注。通常具有高电子效率的电子注,能量分散较大,不利于收集。通过设定电子效率大于25%这个限制条件,来保证了具有高可回收能力的电子注,同时具有较高的输出功率。在遗传算法中调用3维MTSS,用来计算注波互作用后的输出能量和电子能谱图。并对一支Ku波段的螺旋线行波管进行优化设计,从数值计算结果来看,可回收效率提高到了89%,且具有26.9%的电子效率。

关键词：螺旋线行波管效率遗传算法双渐变慢波结构可回收能力

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