一种用于隐身目标探测的外辐射源雷达组网系统

介绍了现有隐身技术以及部分已经装备和正在研制的隐身目标,分类介绍了雷达反隐身的多种措施.在此基础上,提出了外辐射源雷达组网反隐身系统,给出了系统的基本构成、工作原理、系统反隐身原理和系统关键技术.从初步仿真结果可以看出,该系统在工作频率,双/多基地工作方式、组网工作、多频工作和准连续波工作等方面对探测隐身目标均具有一定优势.     

雷达隐身测试的发展与应用

现代武器由于结构复杂,理论分析有着极大的局限性,只能在设计过程中起指导作用,要想精确获取武器装备的隐身特性,必须进行雷达目标特性测量;目前,雷达目标特性测量存在缩比模型测量、目标动态测量和全尺寸目标静态测量等三种方式;文中首先简要地介绍了雷达目标特性研究以及获取方法的发展历程,然后介绍了隐身技术发展以及由此引发的雷达隐身测试,重点分析了国内外测试场地、设备和技术发展状况,并通过针对国内某装备的实测分析归纳了雷达隐身测试技术发展趋势以及各测试场地和方法适用对象。     

基于射频隐身的相控阵雷达搜索控制参量优化设计

机载雷达射频隐身技术对提高飞行器生存能力具有重要意义。 本文研究了机载相控阵雷达基于射频隐身的搜索控制参量优化设计。通过分析截获概率原理 ,给出了目标特征和雷达系统性能对驻留时间和波位间隔等搜索控制参量的影响关系,构建 了目标探测性能与隐身性能约束下的优化模型。仿真获得了满足隐身要求下相控阵雷达的最 优搜索控制参数。     

一种超薄宽带频率选择雷达吸波体的仿真设计

为了减小雷达散射截面,增加飞行器隐身功能,提出了一种新型的超宽频率选择雷达吸波体(FSR)结构.FSR具有带内传输、带外吸收电磁波的特点.设计的FSR结构由无损传输层和有损吸波层组成,中间用空气隔开.无损传输层采用十字缝隙与集总电容构成,用于实现高性能带内传输.吸波层设计了工字形与方形的组合结构,在吸收带内产生两上谐振...     

舰艇水下非声隐身试验与测试技术发展与展望

随着声隐身技术的发展,声探测手段面临挑战,非声探测手段作用日趋显著,以至舰艇水下非声隐身性能越来越受到各国所重视,舰艇水下非声隐身试验与测试技术也得到相应的发展;文中回顾了舰艇水下非声隐身试验与测试技术的发展概况,分析了我国舰艇水下非声(电场、磁场、交变电磁场和红外等)物理场隐身试验与测试技术的特点与存在的问题,指出大力发展固定试验场测试技术是提高舰艇水下非声隐身试验与测试技术水平和能力的必由之路,同时根据我国现有条件,简述了非试验场条件下提升舰艇水下非声隐身试验与测试技术能力的必要性和发展方向。     

反隐身防空导弹制导方法研究

由于目标的雷达散射截面积(RCS)存在各向异性,即在不同观测方向上目标的RCS不同,RCS的大小直接影响导弹导引头的探测距离。研究防空导弹打击隐身目标的问题,为使导弹导引头探测目标的距离达到最远以达到良好的反隐身效果,导弹从隐身目标RCS最大的方向探测并跟踪目标。这就给反隐身防空导弹的制导律提出了入射角要求。本文依据该需求,根据导弹和目标的实时运动轨迹,设计一种基于比例导引律和带终端角度约束导引律的制导方法。仿真结果表明:该制导律可以实现以特定的入射角攻击目标,从而提高导弹的反隐身效果。     

飞机外露物隐身改进设计研究

外露物在一定程度上影响飞机隐身性能,而外露物的共形设计会增加成本。针对低成本准隐身飞机,本文探讨了一种外露物的隐身改进设计,主要采取优化外形,涂敷吸波材料、提升加工工艺等措施实现低成本飞机RCS值的缩减。经过隐身仿真、隐身测试等手段,获取了外露物在不同频点、不同极化下的RCS值,并通过仿真、测试数据对比验证采取隐身改进措施的有效性,并为其它外露物隐身设计提供了设计依据和手段。     

基于混合优化的移动传感器网络反隐身研究

利用隐身目标的空间特性和移动传感器网络中探测器的机动性,提出了一种基于传感器轨迹优化的反隐身策略。针对隐身目标提出雷达波束入射角的概念并给出其表达式,提出基于模拟退火和粒子群的混合轨迹优化方法,提高优化算法的收敛速度、精度以及全局搜索能力。该反隐身策略本质上是通过对移动传感器运动轨迹的规划,充分利用传感器网络带来的信息获取优势,使用集中式检测融合对该组网系统的发现概率和跟踪性能进行仿真,仿真结果表明组网系统反隐身性能明显提高,轨迹优化结果符合工程实际。     

雷达运动目标回波分析

本文详细分析了表征运动目标回波特性的主要参数．提出了动目标回波的模拟方法，并且用实例说明可用不同站点的雷达来观测隐身目标，对进一步研究运动目标和反隐身有较强的工程应用价值。     

组网雷达对等离子体隐身导弹探测能力仿真

等离子体隐身是一项很有发展前途的隐身技术。通过建立某型等离子体隐身导弹模型,分析了其在不同方向和宽频带上的雷达散射截面积(RCS)特性,并通过引入雷达探测概率模型和信息融合机制,针对组网雷达仿真了等离子体隐身导弹的突防能力,仿真结果对等离子体隐身导弹的研究与组网雷达改进探测能力具有参考意义。     

Smart card, the stealth leaker

Information leakage is a major issue for homeland security. When entering and leaving certain countries which are particularly concerned by their national security, electronic devices such as mobile phones and laptops are examined, as well as data storage devices such as USB sticks and mobile hard drives. Technical investigations can be more or less thorough, and might lead up to confiscation of the material in case of doubt. At the same time, the use of smart cards is spreading over the world, mainly as a mode of payment, in public transportation or as SIM cards in mobile phones. These usages are widely adopted, in particular due to the security benefits delivered by these systems. But smart card technologies can also be used in an unconventional way to efficiently hide information crossing national borders. Smart cards have been designed as objects which ensure security in an untrustworthy environment. Their main function is to protect from the outside world and to hide their ways of working. A smart card is a programmable device, close to a very small computer, in which it is possible to hide functionalities impossible to detect. Today, it becomes possible to use a smart card in an unconventional manner, by using its storage and cryptographic capacities to carry information in an undetectable way, under the cover of a harmless common object. The following action could take place in any international airport: a sensitive list of identities and codes which should not been intercepted has to leave the country, the carrier even does not know he brings such of list within his SIM card. In the same way, one could use a smart card as a vector of infection in a closed environment, as modern operating systems now include the protocol layers necessary for their usage.     

计算机网络扫描技术的隐蔽性研究

具有隐蔽性的网络安全扫描器最终所要达到的目标不只是获取目标主机的各种必要信息,而且要在隐蔽的前提下进行扫描,即在扫描过程中尽量使用隐蔽手段,使得扫描行为不被目标机器的管理员或防护系统发现,即便是在被发现的情况下也不能获得真正发起扫描的主机IP。     

Scalable formation control in stealth with limited sensing range

In this paper, a protocol and a control law are designed for a single robot so that a team of such robots can interact and cooperate to reach the displacements from an eligible reference formation. Each robot is equipped with displacement sensors of limited sensing ranges. Communication channels are assumed to be unavailable to the team, and each robot works in stealth mode. The team is scalable such that new robots can be recruited, and existing robots can be dismissed. In order for the team size to be scalable, the extended formation based on relative displacement is established as the reference formation. Thus, using the extended formation as a reference, the control law and the protocol could be flexible. As potential conflicts deflect the robot team from the desired formation, the control law is designed to expose the conflicts to the involved neighboring robots such that the protocol can resolve them. A numerical example is given to illustrate how an extended formation is designed, and a simulation example is conducted to demonstrate the performance and merits of the proposed techniques. Copyright © 2016 John Wiley & Sons, Ltd.     

利用MAK Stealth进行视景仿真开发方法的研究

为了解决分布式仿真的可视化需求,提出了利用MAK Stealth进行视景仿真开发的方法.MAK Stealth以其具有完备的开发接口和良好的可扩展性,使得用户能方便的将其嵌入到自己的应用开发中.根据视景仿真系统的组成,结合MAK Stealth进行视景仿真的开发方法,针对联邦通信和视景驱动控制分析了MAK Stealth的应用开发接口API,依照MAK Stealth的开发流程,实现了三维视景显示系统.系统运行结果表明了利用MAK Stealth进行视景仿真开发是十分方便快捷的.     

Identity fraud: the stealth threat to UK plc

Identity (ID) fraud is one of the fastest growing criminal trends in the UK and costs the British economy around £1.3 billion per year according to the Home Office. It is not just financial loss that victims suffer: it can take up to 300 hours of effort to regain their credibility with banks and credit reference agencies.     

Detecting stealth DHCP starvation attack using machine learning approach

Dynamic Host Configuration Protocol (DHCP) is used to automatically configure clients with IP address and other network configuration parameters. Due to absence of any in-built authentication, the protocol is vulnerable to a class of Denial-of-Service (DoS) attacks, popularly known as DHCP starvation attacks. However, known DHCP starvation attacks are either ineffective in wireless networks or not stealthy in some of the network topologies. In this paper, we first propose a stealth DHCP starvation attack which is effective in both wired and wireless networks and can not be detected by known detection mechanisms. We test the effectiveness of proposed attack in both IPv4 and IPv6 networks and show that it can successfully prevent other clients from obtaining IP address, thereby, causing DoS scenario. In order to detect the proposed attack, we also propose a Machine Learning (ML) based anomaly detection framework. In particular, we use some popular one-class classifiers for the detection purpose. We capture IPv4 and IPv6 traffic from a real network with thousands of devices and evaluate the detection capability of different machine learning algorithms. Our experiments show that the machine learning algorithms can detect the attack with high accuracy in both IPv4 and IPv6 networks.     

Robot formation control in stealth mode with scalable team size

In situations where robots need to keep electromagnetic silent in a formation, communication channels become unavailable. Moreover, as passive displacement sensors are used, limited sensing ranges are inevitable due to power insufficiency and limited noise reduction. To address the formation control problem for a scalable team of robots subject to the above restrictions, a flexible strategy is necessary. In this paper, under the assumption that the data transmission among the robots is not available, a novel controller and a protocol are designed that do not rely on communication. As the controller only drives the robots to a partially desired formation, a distributed coordination protocol is proposed to resolve the imperfections. It is shown that the effectiveness of the controller and the protocol rely on the formation connectivity, and a condition is given on the sensing range. Simulations are conducted to illustrate the feasibility and advantages of the new design scheme developed.     

极化MIMO雷达隐身目标检测性能研究*

多输入多输出(MIMO)雷达使用了远距分布的阵元,它利用了信号的空间分集增益来获取更多的目标信息。极化是另一种可以提高雷达系统性能的分集方式。当应对隐身目标时,传统的极化雷达在某些观测角度会遭受到较大的目标雷达截面积(RCS)衰减,而无法获得较好的检测性能。而在一个雷达系统中同时利用这两种分集增益,可以得到一种比传统极化雷达更具优势的新雷达检测系统——极化统计MIMO雷达,它可以更好地应对隐身目标检测。给出了相应的模型,并推导出了该雷达系统的检测性能解析式。将其与传统相控阵及非极化统计MIMO雷达比较,可以看到极化统计MIMO雷达的检测性能更佳。联系到隐身目标的特性,极化MIMO雷达的检测器特性应对它时具有显著优势。最后,以上方法通过仿真得到了验证。     

A novel stealth Vivaldi antenna with low radar cross section

A novel stealth Vivaldi antenna with low radar cross section (RCS) is proposed in this article that covers the ultrawide band (UWB) from 2 to 12 GHz. As a special scatterer, the antenna can be responsible for the larger part of the total RCS of many military platforms. In this article, the configuration of the metal patch is modified, based on the difference of the current distribution while the antenna radiates and scatters. The monostatic radar cross section of proposed antenna is reduced in most parts of the band with polarized and polarized. Maximally 14 dBsm RCS reduction is achieved. The gain of the proposed antenna and reference antenna are in good agreement in most of the impedance bandwidth. Results are provided to demonstrate that the excellent radiation and perfect stealth performance is achieved. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:255–261, 2015.