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A novel operation mode for spaceborne polarimetric SAR

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Science china(Information sciences) 2011年第4期54卷 884-897页

作者： QI WeiKong 1,2.& YU WeiDong 1 1 Institute of electronics,Chinese {2. of sciences,beijing 100190,china 2.Graduate School of Chinese {2. of sciences,beijing 100039,china 1. Institute of electronics Chinese Academy of Sciences Beijing 100190 China2. Graduate School of Chinese Academy of Sciences Beijing 100039 China

A novel operation mode for spaceborne polarimetric SAR,named polarization space-division adding polarization code-division (PSD-PCD) operation mode,is proposed in this paper through combining polarimetric SAR with elevation digital beam-forming (DBF) on *** a pulse repetition interval the up-chirp LFM sub-pulse is transmitted with horizontal polarization antenna,and with some delay the down-chip LFM subpulse is transmitted with vertical polarization antenna to realize code *** every sub-aperture receives returns from ground,SAR system uses range DBF to separate echoes relative to different sub-pulses in order to realize space *** system PRF is equal to that of single-polarization SAR,and elevation DBF help reduce range ambiguity ***,the main system parameters,including PRF,delay between two sub-pulses,radar equation and ambiguity are analyzed and compared with those of single-polarization *** results demonstrate the feasibility and validity of PSD-PCD operation mode.

关键词： spaceborne synthetic aperture radar (SAR) polarimetry digital beamforming (DBF) operation mode ambiguity ratio polarization space-division polarization code-division

Maximal effective baseline for polarimetric interferometric SAR forest height estimation

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Science china(Information sciences) 2012年第4期55卷 867-876页

作者： ZHOU YongSheng 1,2.3,HONG Wen 1,2.WANG YanPing 1,2.& WU YiRong 1,2.1 National Key Laboratory of Science &Technology on Microwave Imaging,beijing 100190,china 2.I{2. of electronics,Chinese academy of sciences,beijing 100190,china 3 academy of Opto-electronics,Chinese academy of sciences,{12. 100094,china 1. National Key Laboratory of Science & Technology on Microwave Imaging Beijing 100190 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China3. Academy of Opto-Electronics Chinese Academy of Sciences Beijing 100094 China

The concepts of critical baseline and maximal effective baseline have been defined for interferometric SAR (InSAR) DEM application based on the spatial decorrelation (which is a function of baseline).This paper puts forward these two concepts to polarimetric interferometric SAR (Pol-InSAR) forest height estimation *** application makes use of volume decorrelation,which is also a function of *** both the spatial decorrelation and volume decorrelation are considered to determine Pol-InSAR critical and maximal effective *** various decorrelation effects are *** the calculation formula of Pol-InSAR maximal effective baseline are presented and compared to that of *** validation,RVoG-based and PolSARpro-based simulation data and DLR ESAR data are *** concept of Pol-InSAR maximal effective baseline is of practical significance in selection of Pol-InSAR image pairs as well as in the design of further Pol-InSAR systems.

关键词： Pol-InSAR maximal baseline forest height estimation

Experimental results and analysis of sparse microwave imaging from spaceborne radar raw data

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Science china(Information sciences) 2012年第8期55卷 1801-1815页

作者： JIANG ChengLong1,2.3,ZHANG BingChen1,2.ZHANG Zhe1,2.3,HONG Wen1,2.WU YiRong1,2.1S cience and Technology on Microwave Imaging Laboratory,beijing 100190,china {2.,Chinese academy of sciences,beijing 100190,china 3G raduate University of Chinese academy of sciences,beijing 100190,china 1. Science and Technology on Microwave Imaging Laboratory Beijing 100190 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China3. Graduate University of Chinese Academy of Sciences Beijing 100190 China

Sparse microwave imaging is a novel radar framework aiming to bring revolutions to the microwave imaging according to the theory of sparse signal *** compressive sensing(CS)is introduced to synthetic aperture radar(SAR)imaging in recent years,the current SAR sparse imaging methods have shown their advantages over the traditional matched filtering ***,the requirement for these methods to process the compressed range data results in the increase of the hardware *** the SAR sparse imaging method that directly uses the raw data is *** paper describes the method of SAR sparse imaging with raw data directly,presents the analysis of the signal-to-noise ratio(SNR)in the echo signal by combining the traditional radar equation with the compressive sensing theory,and provides the tests on 2.D simulated SAR *** simulation results demonstrate the validity of the SNR analysis,and the good performance of the proposed method while a large percentage of the raw data is *** experiment with RadarSat-1 raw data is also carried out to show the feasibility of processing the real SAR data via the method proposed in this *** method is helpful for designing new SAR systems.

关键词： sparse microwave imaging synthetic aperture radar(SAR)imaging compressive sensing signalto-noise ratio raw data

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.I{2. 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 Beijing 100190 China Institute of electronics Chinese Academy of Sciences Beijing 100190 China Graduate School Chinese Academy of Sciences Beijing 100190 China

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)

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.I{2. of electronics,Chinese academy of sciences,beijing 100190,china 3 Graduate University,Chinese academy of sciences,beijing 100190,china 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

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

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 2.{2. of electronics,Chinese academy of sciences,beijing 100190,china 1. Science and Technology on Microwave Imaging Laboratory Beijing 100190 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 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

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 {2. of sciences,beijing 100190,china 2.Graduate University of Chinese {2. of sciences,beijing 100039,china 1. Institute of electronics Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100039 China

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

The solid lubricating material experiment device for Shenzhou-7 Spaceship

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Science china(Technological sciences) 2010年第9期53卷 2521-2527页

作者： WANG Ke1,2.REN WeiJia1,WANG ShiDa1 & WENG LiJun3 1 academy of Opto-electronics,Chinese academy of sciences,beijing 100190,china 2.Graduate University of Chinese academy of sciences,beijing 100049,china 3 Lanzhou Institute of Chemical Physics,Chinese academy of sciences,Lanzhou 730000,china 1. academy of Opto-electronics Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

A solid lubricating material exposure experiment in space is one of the missions during the seventh manned spaceflight of china,and the key is to develop a device which can be fixed reliably outside of the orbital module and can be fetched conveniently by an astronaut during space *** solid lubricating material experiment device needs to be locked reliably in a vibrating and impacting environment during the launch phase,and should meet the requirement that it can be unlocked and fetched reliably by the astronaut wearing an extravehicular spacesuit via simple operations in orbit in an environment of high and low *** for the device we developed,the environmental characteristic of the mission was analyzed,the mechanical analysis and thermal analysis were carried out,and then a mechanism with functions of mechanical locking,structural self-locking and manual unlocking was *** device was verified by a sequence of experiments and was fetched by the astronaut during the flight of the Shenzhou-7 Spaceship.

关键词： manned spaceflight exposure experiment mechanism unlock

Experimental study of composite medium with simultaneously negative permeability and permittivity

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Science china(Physics,Mechanics & Astronomy) 2004年第1期47卷 64-78页

作者： SUI Qiang1, 2.& LI Fang1 1. Institute of electronics, Chinese {2. of sciences, beijing 100080, china 2. School of Information, beijing Broadcasting Institute, beijing 10002., china Correspondence should be addressed to Sui Qiang (email: suiqiang@***) Received July 2., 2.03 1. Institute of electronics Chinese Academy of Sciences 100080 Beijing China 2. School of Information Beijing Broadcasting Institute 100024 Beijing China

This paper focuses on a composite medium structure that exhibits simultan- eously negative values of effective permeability and permittivity, and our experimental study in an anechoic chamber. The experiment results show that the artificial medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous metallic wires, can have a simultaneously negative effective permeability and permittivity within a frequency region in the microwave regime under certain linearly polarized waves.

关键词： permittivity, permeability, negative index of refraction, split ring resonator, LHM, RHM.