IRST牵引机载预警雷达的探测效能评估与仿真

为定量分析和评估机载红外搜索跟踪系统（IRST）牵引探测模式对雷达探测效能的影响,以雷达探测效能概率作为评估指标,模拟IRST牵引雷达探测的过程,建立基于多波位搜索的牵引成功概率模型,确定满足一定牵引成功概率下的雷达搜索范围,并根据特定的目标特性推导雷达探测效能概率表达式。仿真结果表明,该模式利用红外的高精度角度信息进行牵引,极大缩小了雷达的搜索区域和搜索时间,加快雷达对目标的截获过程,并利用波束驻留时间的增加提高了雷达的发现概率,提升了雷达的探测效能。     

FMCW毫米波雷达多人呼吸检测方法

基于雷达的人体生命体征信号(如呼吸、心跳等)探测在诸多领域具有重要意义。当多个人体目标处于同一平面内,且雷达与多个目标共线时,会导致雷达无法检测较远距离的目标。为此,本文提出一种新的雷达空间布置方案,即将雷达布置在高处,并利用毫米波雷达高分辨率特性从距离维区分多目标,同时结合多种手段辨别人体目标和静止杂波。本文对FMCW毫米波雷达呼吸检测的信号处理流程进行了详细推导,并进行了实验验证。实验结果表明,本文所提方案可以有效地区分人体目标和静止杂波,并准确提取多目标呼吸信号和呼吸频率。此外,针对单部雷达存在空间检测盲区的问题,本文详细讨论了不同雷达数量和空间布置方案下的雷达空间检测盲区,并论证了三部不共线雷达可完全消除雷达空间检测盲区。      

Textural Features for Radar Image Analysis

Texture is an important spatial feature useful for identifying objects or regions of interest in an image. While textural features have been widely used in the analysis of a variety of photographic images, they have not been used for processing radar images. In this paper, we present a procedure for extracting a set of textural features for characterizing small areas in radar images and show that these features can be used for classifying segments of radar images corresponding to different geological formations.     

雷达组网系统对抗有源干扰方法综述

雷达干扰和抗干扰是现代电子战的主要内容之一，是作战双方围绕雷达展开的电磁博弈。受限于有限资源，单基地雷达不足以对抗复杂电子干扰。雷达组网系统将异地部署的多部雷达连接起来对特定区域进行协同探测和信息融合，具有覆盖范围广、获取信息全、测量精度高的优势。更重要的是，雷达组网系统可以通过多视角观测和协同控制，形成对单一干扰机的体系优势。首先简要介绍了雷达组网系统的发展趋势，分析了其抗干扰能力；随后从对抗压制干扰、对抗欺骗干扰和资源管控3个方面对现有雷达组网系统对抗有源干扰方法进行了归纳总结；最后对雷达组网系统对抗有源干扰的发展趋势进行了展望。     

一种新的弱目标自组织模糊分类方法

本文着重研究舰船雷达弱目标的模糊分类问题，讨论了利用Ｋｏｈｏｎｅｎ自组织网络来实现各类目标的二维录属函数生成。     

Laser radar in robotics

In this paper we describe the basic operating principles of laser radar sensors and the typical algorithms used to process laser radar imagery for robotic applications. We review 12 laser radar sensors to illustrate the variety of systems that have been applied to robotic applications wherein information extracted from the laser radar data is used to automatically control a mechanism or process. Next we describe selected robotic applications in seven areas: autonomous vehicle navigation, walking machine foot placement, automated service vehicles, manufacturing and inspection, automotive, military and agriculture. We conclude with a discussion of the status of laser radar technology and suggest trends we see in the application of laser radar sensors to robotics. Many new applications are expected as the maturity level progresses and system costs are reduced     

雷达系统未来发展趋势探析

新的作战对象、作战环境和作战形式对于现代雷达构成了巨大的挑战.需求的牵引和技术的推动,意味着雷达技术在未来必然取得飞跃式的进步.针对雷达在体制架构和专项技术方面的潜在技术突破,重点从技术内涵、必要性及发展现状角度进行了分析和论证.在体制架构方面,重点明确了雷达的分布式组网、智能化认知探测、射频综合化、与平台一体化的技术特点.在专项技术方面,阵列天线呈现为共形化、轻薄化、宽带化的特点;发射器件逐渐采用宽禁带半导体;微系统技术、光电子技术和纳米技术逐步得以应用.     

分布式小型化雷达干扰技术

分布式小型化雷达于扰设备通过搭载平台布放到敌机场、基地等重要区域,对敌防空雷达网或地空武器系统实施近距离干扰,是一种能够有效压制先进体制雷达网的新型电子干扰手段。分析了分布式小型化雷达干扰设备的军事需求,阐述了原理设计与关键技术,并规划其作战使用,进行了作战效能分析。     

几种连续波雷达系统参数设计和信号处理方法

连续波雷达具有结构简单、体积小、无距离盲区、低功耗和低截获、成本低等优点,在军用导航、战场侦察等领域得到广泛应用。文中对双频连续波、多频连续波、步进频率连续波和步进频移键控连续波等4种体制连续波雷达信号处理系统的参数设计和信号处理问题进行了对比分析,得到了各个波形的特点,并通过计算机仿真进行了验证。综合仿真结果和理论分析得到,步进频移键控连续波,能在一个处理周期内对多目标进行分辨。     

舰载雷达低空探测性能分析

结合现役舰载雷达的低空试验数据,研究了减小单部干涉盲区的可行性,给出了一种雷达低空探测距离的计算结果,提出可以警戒探测系统雷达配置进行优化,不同波段电磁波干涉的盲区能够互补,提高低空目标的检测能力,以保证低空目标的连续跟踪。     

基于目标函数的微波超视距雷达天线高度优化方法

利用海上蒸发波导可以使舰载微波超视距雷达实现远距离低空目标探测,然而大气波导内的超折射和多径传播效应会产生不利于目标检测的雷达盲区。该文提出一种基于目标函数的微波超视距雷达天线高度优化方法,针对形成蒸发波导的海-气界面稳定层结、中性层结和不稳定层结3种情况,利用电波传播数值算法和雷达评估模型仿真分析了蒸发波导内特定区域不同目标函数时的雷达目标检测性能,给出了雷达天线高度优化结果。该文方法可以为微波超视距雷达系统设计、探测性能分析和大气环境自适应技术提供参考。     

一种基于正交编码的天基雷达空中目标检测方法

天基雷达由于工作于下视模式,天基雷达接收到的目标回波信号往往会淹没在地球杂波背景中。分析了天基雷达地杂波的产生原因,提出了低PRF时天基雷达空中动目标检测的无杂波区域,然后结合正交编码方式,提出了一种基于正交编码技术的空中目标检测方法。该方法不需要进行复杂的杂波抑制处理,可在一定程度上解决下视雷达面临的强地杂波问题。     

平流层飞艇载雷达系统作战运用分析

临近空间的战略意义日益突出,临近空间飞行器研发也引起了各国的兴趣。类似于地基情报雷达系统可以实现对航空领域的探测一样,基于平流层的飞艇载雷达不仅对临近空间飞行器具有一定的探测能力,而且平流层飞艇载雷达系统还可以通过平台优势实现对低空领域的早期预警。文中通过对比分析平流层飞艇载雷达系统的作战优势,阐述了该雷达系统的几种作战运用方式,重点分析了对抗临近空间目标和低空突防目标的作战运用方法。     

Fifty years of radar

After the almost simultaneous, independent invention of radar in several countries of the world in the mid-1930s, radar development progressed rapidly with its use by both sides during World War II. Since then, radar has been growing through the years in both capability and in applications. In this paper, highlights of the first fifty years of modern radar development are briefly reviewed, current areas of interest are mentioned, and illustrations of many of the radars of the 1980s are given.     

旋转相控阵雷达区域威胁度计算及调度技术研究

旋转相控阵雷达在方位和仰角上均能电子扫描,相对于传统机扫雷达在方位和仰角上能更加灵活地调配资源。为了优化探测效果,需要对探测区域进行方位分区并进行威胁度评估。该文基于旋转相控阵雷达最威胁路径的计算提出一种区域威胁等级评估的方法;通过把每点检测概率等价为代价函数,利用泛函变分将寻找最威胁路径转变为最短路径问题;利用快速行进法求解旅行最短问题满足的程函差分方程,然后利用梯度下降法回溯最威胁路径;最后以240批目标的威胁路径计算为例,给出相应的评估结果。实践结果验证了方法的有效性和正确性。     

Radar Image Processing for Rock-Type Discrimination

Radar images have unique radiometric and geometric characteristics which present unique problems and opportunities for geological application. This paper reviews preprocessing and analytical techniques found useful or promising for applications of radar images to geologic problems such as rock-type discrimination. The use of coherent monochromatic illumination in radar images results in image speckle noise which interferes with characterization of the imaged surface. Median value filtering of the radar images removes speckle with minimal edge effects and resolution degradation. Variations in radar scene illumination due to uncompensated sensor platform motions or antenna pattern effects can be somewhat corrected for by mean and variance equalization in a direction perpendicular to the resulting image gradient. Registration of radar images to a map base and compensation of terrain induced image distortion can be accomplished by registration to digital elevation models and knowledge of imaging geometry. Analysis of SEASAT images with coregistered LANDSAT images indicates that the radar data can make a significant contribution to rock-type discrimination, especially if textural measures are incorporated. The sensitivity of radar backscatter to local slopes makes radar images an excellent medium from which to extract textural measures. Three techniques for extraction of the textural data inherent in the radar images are presented. Computation of image tone variance over various areas can numerically encode image texture. Hue-saturation-intensity split spectrum processing displays low-frequency variations in color while preserving high-frequency detail.     

0.67 THz ISAR成像雷达收发链路设计

介绍了一种工作频率为0.67 THz的逆合成孔径雷达(ISAR)成像系统,该系统作用距离为2 m~8 m,成像分辨力1 cm×1 cm,采用收发分开的天线,发射信号形式为宽带线性调频连续波信号,可应用于安检和无损检测等多个领域。给出了其收发链路的设计方案,对作用距离、发射功率、信号相噪、分辨率、接收灵敏度、接收增益等指标进行了具体论证,并对收发链路各功能模块的组成结构进行了详细描述,为后续开展成像雷达系统的整机研制工作提供理论基础和技术支持。     

Monitoring bird movements by radar

Shortly after the development of radar some 25 years ago, it became apparent that bird movements were often discernible on radar screens. These ``radar angels' in some cases are looked upon as clutter to be eliminated from the radar screen. However, they should be regarded as signals conveying valuable information, since birds can provide a real threat to aircraft, particularly in certain areas and at certain times of the year.     

基于地面雨量计资料的合肥CINRAD雷达降水探测能力分析

利用安徽省31个雨量计每小时的雨量资料及其对应的雷达回波强度资料,分析合肥CINRAD天气雷达6个仰角的回波强度与雨量计观测雨量的相关性,并且通过反射率因子与雨量计雨量相关性的大小分析了合肥CINRAD雷达的降水探测能力.结果表明,对于大多数站点,当雷达仰角为0.5°时反射率因子与雨量计雨量的相关性比较好,雷达对降水的探测能力高;合肥雷达对沿淮、江淮区域站点降水的探测能力比较高,对距合肥较远的安徽边缘地区站点降水的探测能力较低;对于大别山区和皖南山区,雷达对山区上海拔相对高的区域降水的探测能力高,其它地区由于受到山体的阻挡,合肥雷达对对其降水的探测能力较低.     

一种超宽带运动目标检测雷达

阐述了超宽带运动目标检测雷达的工作原理,讨论了把它作为报警器使用时与红外、超声波和微波报警器相比所具有的优点。给出了实验结果和该雷达可能应用的范围,指出了该雷达在人们日常生活中的重要作用。