时分制RWR/ESM处理方法对脉冲丢失的影响

随着战场电磁环境日趋复杂,当前体制下的RWR/ESM正逐渐暴露出其误警率高、漏警 率大和告警时间长等严重问题,其根本原因是由于接收机测量体制引起的脉冲丢失问题,导 致威胁信号源的截获概率降低。结合RWR/ESM测量体制,对时分制频段处理方法引起的脉冲 丢失进行理论分析,推导出工程上可行的应用公式,在此基础上提出了一种基于脉冲密度分 配系统资源的改进方法,并结合仿真结果对两种方法引起的脉冲丢失做了对比分析。研究结 果为今后新型RWR/ESM的研制提供了理论参考。     

机载RWR/ESM信号感知通道中脉冲交叠分析

脉冲交叠是影响RWR/ESM系统效能的重要因素之一。针对典型四通道比幅测向体制的R WR/ESM系统中因分频段、分象限形成的多通道信号感知结构,采用仿真方式,对多辐射源信 号进入RWR/ESM系统后的脉冲交叠情况进行了统计,发现RWR/ESM信道中脉冲交叠的规律： N（N≥2）脉冲交叠比N-1脉冲交叠基本上低一个数量级;且脉冲交叠对不同辐射源信 号序列有不同影响,脉冲交叠同时使得后续的脉冲正确配对比率比较低。     

RWR/ESM系统的“虚警”和“漏警”

RWR/ESM系统中对于诸如“虚警”、“漏警”等概念,经常从理论上和应用上混淆。结合RWR/ESM系统实际信号处理流程和功能,从信号统计检测理论出发,对比雷达/通信相关概念,发现传统意义上的“虚警”、“漏警”已不足以描述RWR/ESM对威胁的检测识别错误,为此基于多元假设检验理论,结合信号威胁等级,重新梳理RWR/ESM系统中信号检测类型的概念,将RWR/ESM 的“虚警”、“漏警”拓展为带威胁级差的“虚警”、“漏警”,增加“同级差错”概念,并初步探讨其概率、代价因子等相关特性。     

美军机载RWR/ESM系统现状与发展

介绍了美军主要机载平台（战斗机、直升机、预警机、电子战飞机）的雷达威胁告警/电子支援措施（RWR/ESM）系统的发展情况,包括型号的更迭、各型号的特点、作用对象及工作模式等方面,然后分析了美军机载RWR/ESM系统涉及的关键技术,最后指出了美军机载RWR/ESM系统的发展趋势。相关内容对从事该领域研究的技术人员具有参考价值。     

随机PRI的LPI波形相参积累

随机脉冲重复频率(PRI)脉冲波形能够增加电子支援措施（ESM）利用重频分选侦收雷达辐射源信号的难度,提高雷达复杂对抗环境下的抗侦收能力。利用非均匀离散傅里叶变换(NUDFT)对这种低截获概率（LPI）波形进行脉冲多普勒（PD）处理时,距离模糊引起目标所处距离门走动,导致目标能量分散至多个模糊距离单元。为此,提出一种基于时间窗口的离散傅里叶变换(TWDFT)算法,实现了距离模糊条件下目标能量的相参积累。对TWDFT算法和加权副瓣抑制的性能进行了分析。仿真结果表明,基于TWDFT的PD处理在距离模糊时不存在目标能量分散问题,通过优化波形设计能够改善加权后目标主副瓣比。     

一种新的雷达告警器虚警机理

雷达告警器(RWR)多用“告警小盒”法进行威胁鉴别,虚警率高是影响雷达告警器效能发挥 的关键问题之一。提出了一种新的告警器虚警机理,即对于RWR中相同频段内、方向也近似 相同的多个脉冲序列组成的信号流中,虽然这些序列各自不相关,且任何单一序列均与某“ 告警小盒”指标相差很大,但可能有某些组合片段符合该“小盒”告警判决条件,从而产生 虚警。仿真结果表明了这种告警机理的存在,而且在某些条件下这种虚警率也相当高。     

用于Mu火箭的无线电制导雷达应答机和指令译码器

日本研制了一种非相参C波段脉冲雷达应答机和制导用的指令译码器,用于测量Mu火箭的轨道和传输无线电制导系统的指令数据。这种应答机具有一个灵敏度高(-70dbm)和动态范围宽(65db),能经受住射频输入电平变化范围大的接收机和一个发射功率大(最小峰值功率400瓦),能发射漂移小,抖动小(30毫微秒)的测距回答脉冲的发射机。发射机和接收机之间的电磁兼容性是通过电磁屏蔽和电路措施来实现的。译码器的设计是利用‘6判3’指令码方式和“验证后执行”的指令序列来减少错误译码概率。这些箭载仪器广泛地使用了国内部件。     

AN/DPN—65(XE—1)应答机

一、概述 AN/DPN-65(XE-1)是C-波段小型脉冲应答机。它由脉冲发射机和晶体视频接收机组成,它是为“台风”导弹设计的。也可用于类似性能的其它导弹、以及载人和无人贺驶飞机,1961年8月交付使用。 AN/DPN-55(XE-1)与地面雷达设备如AN/FPS-16或具有编码脉冲能力的任何其它C-波段雷达设备协同工作,利用该应答机的目的是扩大雷达的跟踪距离。地面雷达利用双脉冲编码     

脉冲多普勒小型数字化中频接收机的设计与实现

针对脉冲多普勒(PD)雷达导引头精密跟踪测量的要求,研究并采用双线插值快速傅里叶变换(FFT)与相位差分鉴频相结合的速度跟踪测量方法和单脉冲角跟踪测量方法。根据数字化中频接收机小型化设计的要求,分别构建以FPGA或DSP为基础的核心子系统,通过对各子系统的有效整合,设计并实现了基于系统功能划分的脉冲多普勒小型数字化中频接收机。测试结果表明,该接收机系统在结构与性能方面均符合设计要求。     

相似性加权Δt直方图脉冲串去交错技术

电子情报数字化侦察接收机中，Δt直方图去交错方法在脉冲串数量较多和脉冲 间隔抖动较大的复杂电磁环境下，不能得到满足数字化自动峰值处理的高度比。在分析一定 纯净比下，以脉冲字参数向量相似性测度对间隔区间记数加权，建立加权复数直方图，对接 收脉冲串进行去交错处理。经过仿真计算，加权复数直方图相比经典方法能明显提高去交错 效果，更易于数字化自动峰值处理。     

Brown＇s Blossom in Britain-China

The overall strategic relationship between U.K. and China is ＂better than ever＂, China- Britain relations have maintained good momentum, with increased high-level exchanges and the reinforcement of strategic mutual trust, with more room for growth in the future.     

Challenge and Opportunity Go Hand in Hand——What Global Economic Agitation Brings to the China's Economy?

Domino effects of the global finance agitation As the origin of the subprime crisis,US financial institutions lost USS45 billion last year,accounted for over half of the total US,EU & Japan loss.Since January 15th,Chtigroup released its financial statement of the 4th quarter,showing a net deficit of USS9.83 billion,which marked the hisoric high of its quarterly deficit.     

Sinosteel：Extraordinary Moves in Industry Chess

Among the Fortune 500 firms,more and more images from China emerge out.On the 2008 list,Sinosteel Corporation,a landmark group of China industries quietly squeezes into the candidate line.As the largest steel service ＆ trade enterprise,its sales reached at RMB 111.24 billion,with a year-on-year increase of 83.03 percent,and the profit grew by 180.03 percent.On the Sinosteel 2008 Work Meeting,the president Huang Tianwen uttered,＂In the coming year,we will work for US$20 billion sales,and look forward to getting a position in Fortune 500 firms for ourselves.＂     

Walk Through Unusual Five Years—— An Exhibitor＇s Canton Fair Course

When the 103rd Canton Fair is approaching, an old friend of Canton Fair, Li Ying from Jiangsu prov-ince recollected his past five years＇ experiences to the grand trade meeting. Each year is special, with some unforgettable memories colored by the year.     

Jean-Pierre Duprieu： Willing to Be A Legate of Sino-French Business

Estaing, former French president, Valery Giscard d＇Estaing attended Sino-French Economic Seminar held in Shanghai in early April and said that the world center has shifted from the west to the east with many European and US companies entering into Asia, and China has the ability to play an important role in the world stage. Estaing, naming himself＂French Confucian＂, then said in Chinese that a cook-group includes 10 people in ancient Chinese soldier system and the cook is in charge of cooking for them. And people who belong to the same cook are actually ＂Partners＂.     

China''''s Stock Market Wave

The annual meeting of the World Economy Forum was held in Davos,a little town in Switzerland,on January 23rd to the 27th this year,with the theme"the Power fo Collaborative Innovation",over 2500 celebrates from ture political and cconomic circles of more than 80 countries and challengred logether to talk about the future of the global economy in 2008,A Forum for the problems and challenges that face whole world,some of the keywords which drew attention during the event were:the U.S.subprime mortgage crisis,soaring energy prices,the economic slowdown in the U.S.ermerging economic bodies,authority funds and the general unpredictable nature of the global economy.     

Trade Promotion from Neighborhood

If you are considering to trade with companies in Japan or expanding your .business to Japan, we are ready to help from the very beginning.＂ You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization （JETRO）. JETRO has committed itself in delivering highly efficient and quality services to meet the demand of internal and external customs including Japanese companies, hence winning a good reputation in the international trade arena. In recent years, with its priority in advancing business cooperation in South and East Asia, JETRO has made great achievement in promoting trade between China and Japan. Therefore, China＇s Foreign Trade interviewed Mr. Yoichi Maine, Deputy Director General of JETRO BEIJING.     

Auto Parts Market Potential Coming into Surface

Looking at the increasingly fierce competition in the world auto market. global automobile manufacturing industry, taking Europe, the U.S. and Japan as representatives, is gradually forming a new type of relationship, mutual cooperation between whole vehicle and parts manufacturers. We can clearly see that auto parts manufacturers have become independent from the whole vehicle manufacturing companies, which means that the former structure of auto industry has greatly changed, and a new relationship,     

China's Auto Industry Steps Forward

Last year,the volume of China's auto trade reached US$66.878 bil- lion,of which imports accounted for US$25.982 billion,a year-on- year increase of 24.45 percent;while ex- ports totaled US$40.896 billion,growing by 45.31 percent.The China Association of Automobile Manufacturers(CAAM) predicts that the number of autos sold in 2008 will break the 1 million barrier for the first time in history,representing an increase of about 20 percent.     

Domino Effect on Electricity and Coal Prices

In the middle of last December, the key purchase contracts for coal used in power generation in 2008 were signed, reflecting a demand for more than 1.085 billion tons. It is important to note that the country＇s five biggest power producers, China Huaneng Group, China Guodian Corporation, China Power Investment Corporation, China Huadian Corporation and China Datang Corporation, had settled on the prices on their purchase contracts, and they are expected to consume 290 million tons of coal for generating electricity,