检索结果-南通市图书馆

Nonuniform stretch processing for the range profile of a target with micro-motion

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第11期16卷 1205-1213页

作者： CHEN Hangyong**, JIANG Weidong, LIU Yongxiang, LI Xiang and GUO Guirong(Institute of Space Electronics Information Technology, National University of Defense Technology, Chang Sha 410073, China) Institute of Space Electronics Information Technology National University of Defense Technology Chang Sha 410073 China

Complex motions such as micro-motions induce complex range-Doppler coupling effect in radar imaging. Hence, it is a challenge to reconstruct a clear range profile of a target with micro-motion. Stretch processing with fine motion compensation cannot perform well while it ties to eliminate the distortion of range profile caused by Doppler effect, because it is difficult to accurately estimate each scattering center velocity during coherent processing interval. Based on nonuniform stretch processing (NSP), a new technology is proposed to decouple range, time and Doppler and then achieve range profile of target with micro-motion. The new technology uses a new synthetic wide-band waveform and has an innovative mathematic interpretation. Statistical properties of the new approach are primarily examined. Typical models of target with micro-motion for high resolution radar are presented. Monte Carlo simulations demonstrate the performance of the new technology and the simulation results confirm our expectations.

关键词： synthetic range profile micro-motion stretch processing Doppler effect.

micro-motion TARGET SENSING BY STEPPED-FREQUENCY CONTINUOUS-WAVE RADAR

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Electronics(China) 2009年第6期26卷 782-787页

作者： Kong Lingjiang Zhou Yongshun Cui Guolong Yang Jianyu School of Electronic Engineering University of Electronic Science and Technology of China Chengdu 611731 China

Mechanical micro-vibration of a target may induce phase modulations on the radar echo,and the vibration can be detected to identify micro-motion target. In this paper,a new method to detect a micro-motion target and obtain its range and micro-motion frequency is proposed in which multiple periods stepped-frequency continuous-wave signal and Moving Target Indication (MTI) filter are adopted. The simulation results illustrate the validity of this method and present the detection of the target range and the vibration frequency. The experiment gives promising results.

关键词： micro-motion micro-Doppler Stepped-frequency continuous-wave MTI (Moving TargetIndication)

A new method of micro-motion parameters estimation based on cyclic autocorrelation function

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2013年第10期56卷 21-31页

作者： NIU Jie LI KangLe JIANG WeiDong LI Xiang KUANG GangYao ZHU HongYu Institute of Space Electronics Information Technology National University of Defense Technology Jiangnan Institute of Computing Technology

Signals with sinusoidal frequency modulation(FM)are the general form of micro-Doppler signals in radar echoes from targets with *** paper derives the cyclic autocorrelation function of a sinusoidal FM signal using its cyclostationary characteristics,and estimates the parameters of amplitude,modulation index,micro-motion period and noise power based on cyclic autocorrelation *** estimation method is robust in noise environment when compared with conventional time-frequency analysis ***,the performances of estimation by utilizing the simulation data and darkroom measurement are shown in *** Monte-Carlo simulation results show that the estimator is asymptotically optimal at SNR above6 dB.

关键词： micro-motion cyclic autocorrelation function sinusoidal frequency modulation signal parameter estimation

Measuring In-Plane micro-motion of micro-Structure Using Optical Flow

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2009年第1期15卷 19-22页

作者：金翠云靳世久栗大超王建林 College of Information Science and Technology Beijing University of Chemical Technology State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University

Optical flow method is one of the most important methods of analyzing motion images. Optical flow field is used to analyze characteristics of motion objects. According to motion features of micro-electronic mechani-cal system (MEMS) micro-structure, the optical algorithm based on label field and neighborhood optimization is presented to analyze the in-plane micro-motion of micro-structure. Firstly, high speed motion states for each fre-quency segment of micro-structure in cyclic motion are frozen based on stroboscopic principle. Thus a series of dynamic images of micro-structure are obtained. Secondly, the presented optical algorithm is used to analyze the image sequences, and can obtain reliable and precise optical field and reduce computing time. As micro-resonator of testing object, the phase-amplitude curve of micro-structure is derived. Experimental results indicate that the meas-urement precision of the presented algorithm is high, and measurement repeatability reaches 40 nm under the same experiment condition.

关键词： micro-electronic mechanical system (MEMS) micro-motion stroboscopic imaging optical flow label field

A jamming method against bistatic SAR based on modulation theory

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2019年第3期30卷 504-510页

作者： RAN Jinhe LI Xiuhe SHEN Yang Electronic Countermeasure Institute National University of Defense Technology

This paper focuses on the jamming problem of bistatic synthetic aperture radar (BiSAR), and a jamming method against BiSAR based on modulation theory is proposed. The proposed jamming method modulates the BiSAR signal with the cosinusoidal phase to generate multi-false targets in range, and further rotates the jammer to generate multi-false targets in azimuth. The range multi-false targets and azimuth multi-false targets form the two-dimensional cover jamming or deception jamming, which can protect the important targets efficiently. The number of false targets, the interval of false targets, and the jamming square can be adjusted flexibly by setting different range jamming parameters and azimuth jamming parameters. The jamming performance and the choosing criteria of jamming parameters are also discussed. Finally, the simulated data verify the effectiveness of the jamming method.

关键词： bistatic synthetic aperture radar (BiSAR) cosinusoidal phase cover jamming micro-motion modulation

CNN Based Classification of Rigid Targets in Space Using Radar micro-Doppler Signatures

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2019年第4期28卷 856-862页

作者： WANG Jun ZHU He LEI Peng ZHENG Tong GAO Fei School of Electronic and Information Engineering Beihang University

micro-motion characteristics play an important role in some applications of radar target classification. In this paper, a classification method of rigid targets in space using radar micro-Doppler signatures is proposed. Based on the attitude kinematics of rigid targets,we analyze feasibility of classification using micro-Doppler signatures by the relationship among inertial properties of typical rigid targets, their micro-motion characteristics,and corresponding modulation to radar echoes. According to the micro-Doppler time-frequency distribution of echoes and the scale of training sample set, Convolutional neural network(CNN) based feature extraction method and softmax Classifier are designed. Simulations are carried out to validate its effectiveness and discuss the impact of observation duration, composition of training data and size of convolutional kernels on its classification robustness and computational cost.

关键词： Inertial model micro-motion Radar micro-Doppler Convolutional neural network

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

组网雷达弹道目标三维微动特征提取

空军工程大学学报（自然科学版） 2014年第4期15卷 34-37页

作者：张栋冯存前贺思三师俊朋魏代春空军工程大学防空反导学院陕西西安710051 294175 部队新疆乌鲁木齐830006

研究弹道目标中的滑动型散射中心三维微动特征提取问题。分析滑动型散射中心的特点,介绍一种基于半周期时延相乘的散射中心微动特征提取方法,建立滑动型散射中心和理想散射中心微动的数学联系,利用组网雷达的多视角特性,从回波信号中提... 详细信息

研究弹道目标中的滑动型散射中心三维微动特征提取问题。分析滑动型散射中心的特点,介绍一种基于半周期时延相乘的散射中心微动特征提取方法,建立滑动型散射中心和理想散射中心微动的数学联系,利用组网雷达的多视角特性,从回波信号中提取参数,通过构造多元非线性方程组,以提取的参数作为变量,求解目标三维微动参数和部分结构特征。仿真实验验证了该方法的有效性。

关键词：组网雷达微多普勒滑动型散射中心三维微动特征 three-dimensional micro-motion feature(换)

Wideband electromagnetic characteristics modeling and analysis of missile targets in ballistic midcourse

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2012年第6期55卷 1655-1666页

作者： XU ShaoKun LIU JiHong WEI XiZhang LI Xiang GUO GuiRong School of Electronic Science and Engineering National University of Defense TechnologyChangsha 410073China

The wideband electromagnetic characteristics of missile targets in midcourse are the foundation of midcourse attack-defense confrontation. This paper proposes a novel electromagnetic scattering modeling method for midcourse targets based on a pre- cise scattering center model, in which the nonideal scattering phenomenon, shielding effect and micro-motion are taken into consideration for the first time. Firstly, a precise scattering center model incorporating both the sliding scattering and artist- tropic scattering is established. Then the change rule of the target attitude is generalized, and a checking method of the scatter- ing center shielding effect is proposed for rotationally symmetric targets. Afterwards, a novel dynamic electromagnetic scat- tering model is presented, where the scattering center model updates along with the variation of the target attitude and can characterize the change of the electromagnetic characteristics of midcourse targets exactly. Finally, in light of the established model, the dynamic electromagnetic characteristics within different attitude angle bounds are analyzed by stages, and some useful conclusions are obtained. Experiment results from the measured data in anechoic chamber verify the validity of the proposed modeling method and relevant analysis.

关键词： ballistic midcourse wideband electromagnetic characteristics micro-motion shielding effect nonideal scattering

PRECISE RADAR TARGET RANGING ESTIMATION BASED ON SLIP MATCHING OF ENVELOPES

在线全文

学校读者我要写书评

暂无评论

PRECISE RADAR TARGET RANGING ESTIMATION BASED ON SLIP MATCHI...