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机载有源相控阵火控雷达技术发展

现代雷达 2024年第2期46卷 1-15页

作者：贲德南京电子技术研究所江苏南京210039

机载火控雷达是战斗机平台获取信息的主要传感器,经历了测距机、脉冲雷达、脉冲多普勒雷达、相控阵雷达的发展历程。文中通过对现有战斗机火控雷达现状分析,结合未来战斗机平台作战需求分析等多个角度分析对机载火控雷达的需求和技术牵... 详细信息

机载火控雷达是战斗机平台获取信息的主要传感器,经历了测距机、脉冲雷达、脉冲多普勒雷达、相控阵雷达的发展历程。文中通过对现有战斗机火控雷达现状分析,结合未来战斗机平台作战需求分析等多个角度分析对机载火控雷达的需求和技术牵引,结合射频一体化、分布式探测、智能蒙皮、隐身探测和芯片化等新兴技术,展望未来机载火控雷达发展趋势,为后续机载火控雷达设计与研究提供参考借鉴。

关键词：有源相控阵机载火控雷达分布式孔径射频隐身

A novel target detection approach based on adaptive radar waveform design

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Chinese Journal of Aeronautics 2013年第1期26卷 194-200页

作者： Wang Haitao Shi Lei Wang Youlin ben de Nanjing Research Institute of Electronics Technology

To resolve problems of complicated clutter, fast-varying scenes, and low signal-clutterratio （SCR） in application of target detection on sea for space-based radar （SBR）, a target detection approach based on adaptive waveform design is proposed in this paper. Firstly, complicated sea clutter is modeled as compound Gaussian process, and a target is modeled as some scatterers with Gaussian reflectivity. Secondly, every dwell duration of radar is divided into several sub-dwells. Regular linear frequency modulated pulses are transmitted at Sub-dwell 1, and the received signal at this sub-dwell is used to estimate clutter covariance matrices and pre-detection. Estimated matrices are updated at every following sub-dwell by multiple particle filtering to cope with fast-varying clutter scenes of SBR. Furthermore, waveform of every following sub-dwell is designed adaptively according to mean square optimization technique. Finally, principal component analysis and generalized likelihood ratio test is used for mitigation of colored interference and property of constant false alarm rate, respectively. Simulation results show that, considering configuration of SBR and condition of complicated clutter, 9 dB is reduced for SCR which reliable detection requires by this target detection approach. Therefore, the work in this paper can markedly improve radar detection performance for weak targets.

关键词： Adaptive waveform design Generalized likelihood ratio test Multiple particle filter Principal component analysis Radar systems Space-based radar

基于数字孪生和强化学习的低空智联网协同认知干扰

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数据采集与处理 2024年第1期39卷 15-30页

作者：沈高青蔡圣所雷磊贲德南京航空航天大学公共实验教学部南京211106 南京航空航天大学电子信息工程学院南京211106

针对低空智联网协同认知干扰决策过程中,多架电子干扰无人机对抗多部多功能雷达的干扰资源分配问题,提出了一种基于数字孪生和深度强化学习的认知干扰决策方法。首先,将协同电子干扰问题建模为马尔可夫决策问题,建立认知干扰决策系统模... 详细信息

针对低空智联网协同认知干扰决策过程中,多架电子干扰无人机对抗多部多功能雷达的干扰资源分配问题,提出了一种基于数字孪生和深度强化学习的认知干扰决策方法。首先,将协同电子干扰问题建模为马尔可夫决策问题,建立认知干扰决策系统模型,综合考虑干扰对象、干扰功率和干扰样式选择约束,构建智能体动作空间、状态空间和奖励函数。其次,在近端策略优化(Proximal policy optimization,PPO)深度强化学习算法的基础上,提出了自适应学习率近端策略优化(Adaptive learning rate proximal policy optimization,APPO)算法。同时,为了以高保真的方式提高深度强化学习算法的训练速度,提出了一种基于数字孪生的协同电子干扰决策模型训练方法。仿真结果表明,与已有的深度强化学习算法相比,APPO算法干扰效能提升30%以上,所提训练方法能够提高50%以上的模型训练速度。

关键词：多无人机协同认知干扰决策多功能雷达深度强化学习数字孪生

Estimation of multipath parameters in wireless communications using multi-way compressive sensing

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Journal of Systems Engineering and Electronics 2015年第5期26卷 908-915页

作者： Fangqing Wen Gong Zhang de ben College of Electronics and Information Engineering Nanjing University of Aeronautics and Astronautics Key Laboratory of Radar Imaging and Microwave Photonics Ministry of Education Nanjing Research Institute of Electronics Technology

This paper addresses the problem of joint angle and delay estimation(JAde) in a multipath communication scenario. A low-complexity multi-way compressive sensing(MCS) estimation algorithm is proposed. The received data are firstly stacked up to a trilinear tensor model. To reduce the computational complexity,three random compression matrices are individually used to reduce each tensor to a much smaller one. JAde then is linked to a low-dimensional trilinear model. Our algorithm has an estimation performance very close to that of the parallel factor analysis(PARAFAC) algorithm and automatic pairing of the two parameter sets. Compared with other methods, such as multiple signal classification(MUSIC), the estimation of signal parameters via rotational invariance techniques(ESPRIT), the MCS algorithm requires neither eigenvalue decomposition of the received signal covariance matrix nor spectral peak searching. It also does not require the channel fading information, which means the proposed algorithm is blind and robust, therefore it has a higher working efficiency.Simulation results indicate the proposed algorithm have a bright future in wireless communications.

关键词： multipath channel delay estimation direction-ofarrival(DOA) estimation multi-way compressive sensing(MCS)

Geochemistry, mineral paragenesis and geothermal conditions of oreforming fluids from the Ain El Bey Cu–Fe deposit: potential occurrence of native gold and precious metal traces (North African orogenic belt, Northern Tunisia)

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Acta Geochimica 2024年第2期43卷 366-384页

作者： Rania ben Aissa Wiem ben Aissa Said Tlig Lassaad ben Aissa Abdessalem ben Haj Amara Faculty of Science of Bizerte University of Carthage7021 ZarzounaBizerteTunisia Laboratoire de Recherche Ressources Materiaux et EcosystemesUniversity of Carthage7021 ZarzounaBizerteTunisia department of Geology University Claude Bernard Lyon 169622 VilleurbanneFrance Faculty of Science of Tunis University of Tunis-El ManarRommana1068 TunisTunisia

The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization related to various hydrothermal fluid circulations. Petromineralogical studies indicate a rich mineral paragenesis with a minimum of seven mineralization phases and, at least, six pyrite generations. As is also the case for galena and native silver, native gold is observed for the first time as inclusion in quartz which opens up, thus, new perspectives for prospecting and evaluating the potential for noble metals associated with the mineralization. Scanning Electron Microscope--Energy Dispersive Spectroscopy and Transmission electron microscopy analyses show, in addition, a large incorporation of trace elements, including Ag and Au, in mineral structures such as fahlores(tetrahedrite-tennantite) and chalcopyrite ones. The mineral/mineral associations, used as geothermometers, gave estimated temperatures for the mineralizing fluids varying from 254 to 330 ℃ for phase Ⅲ, from 254 to 350 ℃ for phase Ⅳ, and from 200 to 300 ℃ for phases Ⅴ and Ⅵ. The seventh and last identified mineralization phase, marked by a deposit of native gold, reflects a drop in the mineralizing fluid’s temperature(development of precious metal research and the revaluation of the Cu–Fe ore deposit at the Ain El Bey abandoned mine, as well as at the surrounding areas fitting in the geodynamic framework of the Africa-Europe plate boundary.

关键词： Ore-formingﬂuids Mineral geochemistry Mineral geothermometers Native silver-gold Ain El Bey Ore deposit North Tunisia

Schemes for synthesizing high-resolution range profile with extended OFDM-MIMO

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Journal of Systems Engineering and Electronics 2017年第3期28卷 424-434页

作者： Xinhai Wang Gong Zhang Fangqing Wen de ben Key Laboratory of Radar Imaging and Microwave Photonics Nanjing University of Aeronautics and AstronauticsNanjing 211106China College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China Electronic and Information School Yangtze UniversityJingzhou 434023China

Two novel schemes are proposed to synthesize high resolution range profile (HRRP) based on co-located multiple-input multiple-output (MIMO) system in the context of the joint radar and communication system. The difference between two schemes is the pattern of selecting pulses, which depends on the demand for the velocity information. The system, a type of frequency diverse array (FDA), takes full advantage of the phase-coded orthogonal frequency division multiplexing (OFDM) signal. Furthermore, the complete discrete form of the phase-coded OFDM echoes is utilized to derive the HRRP processing. The velocity estimation in the second scheme aims to eliminate velocity ambiguity, and high velocity can be retrieved exactly. Meanwhile, the imaging method is investigated with random frequency coding applied to an array. The desired performance of resolving velocity ambiguity and suppressing noise is shown by means of comparisons with previous work. The advantages in the radar imaging and the significance of the work are concluded in the end.

关键词： high-resolution range profile (HRRP) multiple-input multiple-output system (MIMO) orthogonal frequency division multiplexing (OFDM) joint radar-communication system

Adapitive waveform design for distributed OFDM MIMO radar system in multi-target scenario

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Chinese Journal of Aeronautics 2018年第3期31卷 567-574页

作者： Haitao WANG Junpeng YU Wenzhen YU de ben Nanjing Research Institute of Electronics Teehnology Nanjing 210039 China

In order to improve detection and estimation performance of distributed OrthogonalFrequency-Division Multiplexing（OFDM） Multiple-Input Multiple-Output（MIMO） radar system in multi-target scene, we propose a novel approach of Adaptive Waveform design（AWD） based on a constrained Multi-Objective Optimization（MOO）. The sparse measurement model of this radar system is derived, and the method based on decomposed Dantzig selectors is applied for the sparse recovery according to the block structures of the sparse vector and the system matrix. An AWD approach is proposed, which optimizes two objective functions, namely minimizing the upper bound of the recovery error and maximizing the weakest-target return, by adjusting the complex weights of the emitting waveform amplitudes. Several numerical simulations are provided and their results show that the detection and estimation performance of the radar system is improved significantly when this MOO-based AWD approach is applied to the distributed OFDM MIMO radar system. Especially, we verify the effectiveness of our AWD approach when the available samples are reduced severally and the technique of compressed sensing is introduced.

关键词： Adaptive waveform design Compressed sensing Distributed radar Multi-objective optimization Multiple-input multipleoutput Orthogonal-frequencydivision multiplexing

Angle estimation for bistatic MIMO radar with unknown mutual coupling based on three-way compressive sensing

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Journal of Systems Engineering and Electronics 2017年第2期28卷 257-266页

作者： Xinhai Wang Gong Zhang Fangqing Wen de ben Wenbo Liu Key Laboratory of Radar Imaging and Microwave Photonics Ministry of EducationNanjing University of Aeronautics and Astronautics Nanjing 210016 China Electronic and Information School Yangtz University Jingzhou 434023 China College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

The problem of angle estimation for bistatic multiple-input multiple-output radar in the present of unknown mutual coupling (MC) is investigated, and a three-way compressive sensing (TWCS) estimation algorithm is developed. To exploit the inherent multi-dimensional structure of received data, a trilinear tensor model is firstly formulated. Then the de-coupling operation is followed. Thereafter, the high-order singular value decomposition is applied to compress the high dimensional tensor to a much smaller one. The estimation of the compressed direction matrices are linked to the compressed trilinear model, and finally two over-complete dictionaries are constructed for angle estimation. Also, Cramer-Rao bounds for angle and MC estimation are derived. The proposed TWCS algorithm is effective from the perspective of estimation accuracy as well as the computational complexity, and it can achieve automatically paired angle estimation. Simulation results show that the proposed method has much better estimation accuracy than the existing algorithms in the low signal-to-noise ratio scenario, and its estimation performance is very close to the parallel factor analysis (PARAFAC) algorithm at the high SNR regions. ? 2017 Beijing Institute of Aerospace Information.

关键词： Channel estimation Codes (symbols) Compressed sensing Cramer Rao bounds Feedback control MIMO radar MIMO systems Radar Radar signal processing Signal reconstruction Singular value decomposition Telecommunication repeaters Tensors

Polyphase orthogonal sequences design for opportunistic array radar via HGA

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Journal of Systems Engineering and Electronics 2013年第1期24卷 60-67页

作者： Shufeng Gong Weijun Long Hao Huang de ben Minghai Pan College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Nanjing Research Institute of Electronics Technology

Opportunistic array radar （OAR） is a new generation radar system based on the stealth of the platform, which can improve the modern radar performance effectively. designing the orthogonal code sets with low autocorrelation and cross-correlation is a key issue for OAR. This paper proposes a novel hybrid genetic algorithm （HGA） and designs the polyphase orthogonal code sets with low autocorrelation and cross-correlation properties, which can be used in the OAR system. The novel algorithm combines with simulated annealing （SA） and genetic algorithm （GA）, adds in keeping best individuals and competition in small scope, and introduces grey correlation evaluation to evaluate fitness function. These avoid the premature convergence problem existed in GA and enhance the global searching capability. At last, the genetic results are optimized to obtain the best solution by using greedy algorithm. The simulation results show that the proposed algorithm is effective for the design of orthogonal phase signals used in OAR systems.

关键词： hybrid genetic algorithm （HGA） grey correlation evaluation opportunistic array radar （OAR） orthogonal signal.