Analysis of the joint detection capability of the SMILE satellite and EISCAT-3D radar

The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)satellite is a small magnetosphere–ionosphere link explorer developed cooperatively between China and Europe.It pioneers the use of X-ray imaging technology to perform large-scale imaging of the Earth’s magnetosheath and polar cusp regions.It uses a high-precision ultraviolet imager to image the overall configuration of the aurora and monitor changes in the source of solar wind in real time,using in situ detection instruments to improve human understanding of the relationship between solar activity and changes in the Earth’s magnetic field.The SMILE satellite is scheduled to launch in 2025.The European Incoherent Scatter Sciences Association(EISCAT)-3D radar is a new generation of European incoherent scatter radar constructed by EISCAT and is the most advanced ground-based ionospheric experimental device in the high-latitude polar region.It has multibeam and multidirectional quasi-real-time three-dimensional(3D)imaging capabilities,continuous monitoring and operation capabilities,and multiple-baseline interferometry capabilities.Joint detection by the SMILE satellite and the EISCAT-3D radar is of great significance for revealing the coupling process of the solar wind–magnetosphere–ionosphere.Therefore,we performed an analysis of the joint detection capability of the SMILE satellite and EISCAT-3D,analyzed the period during which the two can perform joint detection,and defined the key scientific problems that can be solved by joint detection.In addition,we developed Web-based software to search for and visualize the joint detection period of the SMILE satellite and EISCAT-3D radar,which lays the foundation for subsequent joint detection experiments and scientific research.

基于S7-1500 GRAPH语言的交通灯控制系统设计

文章介绍了一种基于S7-1500 GRAPH语言的交通灯控制系统设计方法。通过对系统需求的分析和功能设计的实现,成功地实现了交通灯控制逻辑程序的设计和实现,并通过调试和测试结果分析,验证了系统的运行效果和稳定性。文章还对S7-1500 GRAPH语言在交通灯控制系统中的应用效果进行了评估,并探讨了进一步改进和优化方案。

First assessment of Noise-Equivalent Sigma-Zero in GF3-02 TOPSAR mode with sea surface wind speed retrieval

Gaofen-3-02(GF3-02)is the first C-band synthetic aperture radar(SAR)satellite with terrain observation with progressive scans of SAR(TOPSAR)imaging mode in China,which plays an essential role in marine environment monitoring.Given the weak scattering characteristics of the ocean,the system thermal noise superimposed on SAR images has significant interference,especially in cross-polarization channels.Noise-Equivalent Sigma-Zero(NESZ)is a measure of the sensitivity of the radar to areas of low backscatter.The NESZ is defined to be the scattering cross-section coefficient of an area which contributes a mean level in the image equal to the signal-independent additive noise level.For TOPSAR,NESZ exhibits the shape of the SAR scanning gain curve in the azimuth and the shape of the antenna pattern in the range.Therefore,the accurate measurement of NESZ plays a vital role in the application of spaceborne SAR sea surface cross-polarization data.This paper proposes a theoretical calculation method for the NESZ curve in GF3-02 TOPSAR mode based on SAR noise inner calibration data and the imaging algorithm.A method for correcting the error existing in the theoretical curve of NESZ is also proposed according to the relationship between sea surface backscattering and wind speed and the same characteristics of target scattering in the overlapping area of adjacent sub-swaths.According to assessment with wide-swath TOPSAR cross-polarization data,the GF3-02 TOPSAR mode has a very low thermal noise level,which is better than−33 dB at the edge of each beam,and controlled below−38 dB at the center of the beam.The two-dimensional reference curves of the NESZ of each beam are provided to the GF3-02 TOPSAR users.After discussing the relationship between normalized radar cross section(NRCS)and wind speed,we provide a formula for NRCS related to wind speed and radar incidence angle.Compared with the NRCS derived from this formula and the NESZ-subtracted NRCS of SAR images,the bias is−0.0048 dB,the Root Mean Square Error is 1.671 dB and the correlation coefficient is 0.939.

结合最近邻图模型的稀疏ISAR成像方法

逆合成孔径雷达(Inverse Synthetic Aperture Radar,ISAR)稀疏成像方法可提供图像对比度高、旁瓣干扰少的成像结果 .稀疏成像以场景或目标散射率分布具有稀疏性为前提,待成像目标场景的稀疏特性决定了最终成像质量. ISAR目标场景的自然稀疏特性着重刻画点状特征,变换域稀疏表示可增强目标图像的纹理等通用特征.通过学习获得的稀疏变换字典,可自适应于待成像的ISAR目标场景,找到面向ISAR目标图像块的特有稀疏表示.但是,图像块的特有稀疏表示中忽略了待成像目标场景中目标的几何特征信息.最近邻图模型可建立给定数据的几何特征描述算子,刻画出给定数据的几何特征信息.本文利用最近邻图模型来刻画待成像目标场景中目标的几何特征信息,并映射到待成像目标场景的特有稀疏表示中;提出结合最近邻图模型的ISAR稀疏成像方法,用于不同类别实测ISAR数据成像.相比已有的ISAR稀疏成像方法,所提成像方法可获得目标轮廓更清晰的成像结果,成像所需时间平均减少10.4%.

基于可视图深度学习的雷达天线扫描样式识别

针对相控阵雷达扫描信号难识别的问题,提出一种基于可视图深度学习的雷达扫描样式识别方法。首先,分析了7种常见的雷达天线扫描样式。然后,将接收到的天线主瓣照射幅度与脉冲到达时间之间的变化趋势转换为可视图矩阵。最后,构建深度网络模型,验证扫描样式识别的效果。试验结果表明,基于可视图深度学习的雷达扫描样式识别方法对7种扫描样式的整体识别准确率在90%以上,并对低信噪比的信号有很好的处理适应性。

雷达知识图谱构建方法及应用

描述雷达及其属性的非结构化文本信息分散在互联网各处,信息量丰富但数据格式多样,难以直接处理和分析,构建雷达知识图谱能够有效解决这一问题.为此本文首先梳理了构建雷达知识图谱的流程;然后结合雷达领域的特点同时参考七步法,构建了雷达知识图谱的本体层;最后利用互联网文本语料作为数据源,对通用信息抽取(UIE)模型进行微调,完成了知识抽取,构建了雷达知识图谱.应用结果表明,构建的雷达知识图谱可为业内人员提供参考查询的功能,对搭载雷达的战斗平台进行高维画像;同时可作为底层数据库进一步开发,支撑完成上层应用.

电子战领域知识图谱的研究现状和展望

随着现代电子战的不断发展,电子战领域的数据呈现出爆炸式的增长,而利用知识图谱可以很好地组织和高效利用电子战领域的数据.针对电子战领域知识图谱的构建和应用研究还不完善的现状,综述了电子战领域知识图谱的发展状况,归纳了我国在该领域的研究成果;然后对知识图谱在电子战领域的未来发展方向进行展望.

Few-shot incremental radar target recognition framework based on scattering-topology properties

The continuous emergence of new targets in open scenarios leads to a substantial decrease in the performance of Inverse Synthetic Aperture Radar(ISAR)recognition systems.Also,data scarcity further exacerbates the challenge of identifying new classes of ISAR targets.In this paper,a few-shot incremental target recognition framework based on Scattering-Topology Properties(STPIL)is proposed.Specifically,STPIL extracts scattering-topology properties of ISAR targets as recognition features.Meanwhile,the pseudo-incremental training strategy effectively alleviates the algorithm’s forgetting of old knowledge,and improves compatibility with new classes.Besides,a feature embedding network,with few parameters,is designed based on the graph neural network.This embedding network is highly adaptable to changes in data distribution.Additionally,STPIL fully considers the joint distribution and marginal distribution in scattering features,and uses the Brownian distance metric module to make the scattering-topology features more discriminative.Experimental results on both the simulation dataset and the public measured data indicate that STPIL can effectively balance new classes with old classes,and has superior performance to other advanced methods in the incremental recognition of targets.

基于改进的高斯混合模型和图割模型的水体图像提取算法

合成孔径雷达具有全天时、全天候成像,观测范围广、成图周期短等特点,使其在水体提取中的应用具有明显优势。但是在湖泊提取中,已有算法易受湖泊周围环境噪声的干扰,运行效率低。针对此,提出一种将改进的高斯混合模型(GMM)与图割模型相结合的检测方法。先是利用两级Otsu阈值方法以获取湖泊的初始分割图,将对其计算得到的参数集作为GMM初始参数,其后应用最大期望算法(EM)迭代求取GMM的最佳参数,最后基于图割模型精准定位水体位置。实验结果表明初始参数越精确,水体轮廓越清晰,引入两级Otsu算法不仅可大幅度减少EM算法的迭代次数,且与预处理中的下采样相结合有效地提高了算法的运行速度。此外,改进传统图割模型的能量函数使得无需后处理即可得到精确的湖泊边界。

4D毫米波雷达稀疏点云下的连续帧隐空间法线估计

针对毫米波连续调频雷达在室外运动场景下点云数据稀疏和空间配准精度低的问题,本文提出了一种轻量级空间配准方法。该方法适用于室外运动场景下毫米波雷达连续多帧之间的点云处理,能在没有位姿传感器辅助的情况下,通过时空图神经网络准确估计相邻多帧点云的隐空间法线,并将每帧雷达点云数据转换到统一的观测坐标系中,从而实现四维点云的多帧融合与场景配准。实验结果表明,该方法不仅能准确评估四维点云的空间姿态,还能有效校正和融合每帧点云的坐标,在运动及震动过程中实现点云坐标的精准配准。此外,该算法还能显著提高点云成像的密度,增强图像的精度和可读性,同时适用于静态和动态目标的成像,为毫米波雷达在室外运动场景的应用提供了有力支持。

基于S7-300 PLC的机械手自动搬运系统控制研究

机械手自动搬运系统是现代自动化控制系统的重要组成部分,可以大大提高自动化生产效率。随着自动控制精度越来越高,对机械手行走位置精准控制显得尤为重要。本文介绍了基于S7-300 PLC的机械手自动搬运系统的组成,控制机械手行走的步进电机及驱动器优点及程序控制方法,以及应用顺序功能图语言GRAPH进行系统自动运行控制的程序设计方法。应用GRAPH语言编程,程序结构清晰、调试方便,设计周期短。配合顺序功能图设计,使用了工作过程中工作状态、位置等识别的标志位,使程序更加简单明了。对系统调试过程中出现的问题进行分析,提出了解决方法。

用Microsoft Graph绘制二元合金相图

介绍了用Microsoft Graph绘制金属的冷却曲线以及二元合金的温度-组成图的方法。该绘制方法方便、快捷、易于掌握,而且能同时绘制多个相图,并且可以对绘出的相图进行各种平移操作、类型转换、对比分析和曲线拟合,从而大大提高了工作效率。用该法绘制出的相图准确、美观。

基于S7-1500的物料混合系统设计

物料混合系统在化工、制药、炼油等行业得到广泛的应用,系统多利用PLC实现自动混合物料控制。文章使用西门子S7-1500的PLC和西门子HMI设计物料混合系统的硬件,采用一种新的以太网通信系统Profinet通信方式,结合TIA Portal编程软件的GRAPH和LAD编程语言,实现物料混合系统的自动控制。

OPTIMIZATION ON ANTENNA PATTERN OF SPACEBORNE SAR WITH IMPROVED NSGA-Ⅱ

Optimization of antenna array pattern used in a spaceborne Synthetic Aperture Radar (SAR) system is considered in this study. A robust evolutionary algorithm, Non-dominated Sorting Genetic Algorithms (the improved NSGA-Ⅱ), is applied on a spaceborne SAR antenna pattern design. The system consists of two objective functions with two constraints. Pareto fronts are generated as a result of multi-objective optimization. After being validated by a test problem ZDT4, the algorithms are used to synthesize spaceborne SAR antenna radiation pattern. The good results with low Ambi- guity-to-Signal Ratio (ASR) and high directivity are obtained in the paper.

Kravchenko probabilityweight functions in problems of radar signals correlation processing

In this report the combined method of correlation radar signal(RS)processing based on the theory of atomic functions(AF)is examined.Examples of using of new Kravchenko probability weight functions(WF)designs are presented.Quality functional to estimate accuracy and efficiency of RS processing for concrete physical models is constructed.It is shown that the proposed approach significantly improves the quality of the coherent analysis of RS.

Preface: The Chang'e-3 lander and rover mission to the Moon

The Chang＇e-3 （CE-3） lander and rover mission to the Moon was an in- termediate step in China＇s lunar exploration program, which will be followed by a sample return mission. The lander was equipped with a number of remote-sensing instruments including a pair of cameras （Landing Camera and Terrain Camera） for recording the landing process and surveying terrain, an extreme ultraviolet camera for monitoring activities in the Earth＇s plasmasphere, and a first-ever Moon-based ultravi- olet telescope for astronomical observations. The Yutu rover successfully carried out close-up observations with the Panoramic Camera, mineralogical investigations with the VIS-NIR Imaging Spectrometer, study of elemental abundances with the Active Particle-induced X-ray Spectrometer, and pioneering measurements of the lunar sub- surface with Lunar Penetrating Radar. This special issue provides a collection of key information on the instrumental designs, calibration methods and data processing pro- cedures used by these experiments with a perspective of facilitating further analyses of scientific data from CE-3 in preparation for future missions.

A New Characterization of Simple K_3-groups

In this paper, We show that the simple K\-3-groups can be characterized by the orders of their maximal abelian subgroups. That is, we have Theorem Let G be a finite group and M a simple K \-3-group. Then G is isomorphic to M if and only if the set of the orders of the maximal abelian subgoups of G is the same as that of M .

一种基于一致性的分布式天基雷达组网空中目标高度估计与定位方法

单颗天基探测雷达对空中目标跟踪定位时,由于存在俯仰角信息缺失及量测的非线性等问题,目标高度估计误差大。多天基雷达组网为解决该问题提供了一种手段。同时,考虑系统的低计算复杂度、低通信开销、高精度、高可靠性等需求,该文提出了一种基于一致性的分布式天基雷达组网空中目标高度估计与定位方法。首先,给出了空中目标运动模型与天基雷达量测模型;然后,基于概率图模型理论,建立了多天基雷达组网融合多帧量测下目标跟踪定位问题的因子图模型;基于一致性融合,在多个局部目标运动状态之间建立耦合关系;结合粒子滤波与信度传播,建立了非参数信度传播在多天基雷达组网融合跟踪因子图上的消息表示与迭代计算规则;最后通过仿真验证了算法性能。仿真结果表明,与分布式一致扩展卡尔曼滤波算法相比,所提算法目标高度估计精度提升35.3%,有效提升了天基雷达目标定位性能。

The Optimizing Model and Its Solution for Making Train Working Graph with Computer on Separative Division of Double－Track Lines

The authoros specialize in the field of optunization and automatic programme oftrain working graph. In this peper, at frist, a mixed 0-1 integer progranimingmodel about this problem for duuble-track lines is set up, then the principle andProcess of selution are stated, with an application exaiiiple put forward.

The Generalization of Signed Domination Number of Two Classes of Graphs

Let be a graph. A function is said to be a Signed Dominating Function (SDF) if holds for all . The signed domination number . In this paper, we determine the exact value of the Signed Domination Number of graphs and for , which is generalized the known results, respectively, where and are denotes the k-th power graphs of cycle and path .