An integrated maritime surveillance system based on high-frequencysurface-wave radars. 1. Theoretical background and numerical simulations

An integrated maritime surveillance (IMS) system, based on high-frequency surface-wave radars (HFSWR), is described. IMS provides low-cost, 24-hour, real-time, over-the-horizon surveillance of large ocean areas, out to the 200 nautical mile Exclusive Economic Zone (EEZ). The system can be used to coordinate search and rescue operations, and to combat smuggling, drug trafficking, illegal dumping of pollutants, and other undesirable activities. The major challenges in using HFSWR are (i) operating within the crowded HF spectrum; and (ii) maintaining effective operation in high environmental noise, ocean clutter, ionospheric clutter and other undesirable sources of interferences. The system is outlined and these problems are addressed. Numerical simulation, as well as stochastic modeling, are presented to demonstrate the physics behind the system     

Target reflectivity and RCS interactions in integrated maritimesurveillance systems based on surface-wave high-frequency radars

Abnormal fluctuations have been observed in detected power levels of some of the targets during trials of the integrated maritime surveillance system (IMS) based on the Canadian east coast surface-wave high-frequency radar (HFSWR). The power level of most of the surface and air targets fluctuated within measurement-error limits (a few dB) during consecutive detections. These fluctuations have been observed to be more than 15 dB for a huge oil platform and nearby large tankers. These fluctuations are quite different than those observed in microwave radars, such as pulse-to-pulse or scan-to-scan fluctuations (which are modeled as different Swerling-type targets), and as are mentioned in most of the classical radar handbooks. In order to understand the reason behind these fluctuations, the behavior of the target reflectivity and radar cross section (RCS) of surface and air targets and their mutual RCS interaction were investigated. Powerful numerical techniques were used to model and understand the target reflectivity and RCS interactions, mostly in the resonance regime. Different scenarios were created, and the mutual RCS behavior of nearby large targets (such as oil tankers and/or fixed offshore oil platforms) as they were maneuvering were modeled. It was shown that 10 dB to 20 dB RCS fluctuations should be expected when targets interact, especially in the resonance regime     

防空情报雷达反干扰能力综合分析和评估

针对在复杂电磁环境下防空情报雷达反干扰能力评估难的问题,分析了雷达反干扰能力评估的方法和准则,根据防空情报雷达自身特点,依据多属性决策方法,分别建立了分辨率、功率、频率、雷达体制和反干扰技术措施五个属性的评估模型,在此基础上建立了反干扰能力综合评估模型。在想定干扰环境下,应用评估模型对三种不同型号防空情报雷达的反干扰能力进行了计算。评估模型考虑了影响防空情报雷达反干扰能力的各种因素,所得结果能准确地反映出实际情况,具有一定的应用价值。     

机载对海雷达发展态势分析

受地球曲率的限制,机载对海雷达相对舰载或地面雷达,对海面目标和低空飞行目标的作用距离更有优势。机载对海雷达已经历了三个发展阶段,从完全机械扫描体制发展为二维相扫体制。机载对海雷达正面临小目标探测、作战情报质量和复杂电磁环境三大挑战。文中提出了机载对海雷达的发展趋势为提升小目标探测能力、优化情报质量及推广有源相控阵体制的应用。     

中央电子胎儿监护用于产前监测的临床价值

目的:探讨中央电子胎儿监护系统用于产前监测的临床价值.方法:对2005年6月至2005年12月在我院住院分娩的197例孕妇(研究组)进行中央电子胎儿监护,与2001年6月至2001年12月在我院住院分娩的未行中央电子胎儿监护的200例孕妇(对照组)进行比较,分析两组胎儿监护结果和围产儿结局.结果:研究组胎心异常检出率(30.8%)较对照组(17.2%)明显增加(P＜0.05).研究组异常图形为变异减速,百分率为28.8%,与对照组(12.4%)比较,差异均有显著性(P＜0.05).研究组新生儿窒息发生率为4.0%,低于对照组的8.4%(P＜0.05).两组剖宫产率和产钳助产率差异无显著性(P＞0.05).结论 利用中央电子胎儿监护系统进行产前监测,可改善围产儿预后,减少手术产率.     

Intelligent video surveillance system using two-factor human information

Recently, with the increase of terror and crime the utilization of security surveillance systems including CCTV increases. However, the issues of privacy invasion occurred by exposing the data recorded through video surveillance system have been raised. In this paper, the intelligent video surveillance system which can prevent the invasion of privacy and complement the monitoring function which will be declined by privacy protection is proposed. The proposed system checks the identification using the smart card and camera at the entrance and extracts the height and color information of object. Inside of the building where only a camera is installed without smart card terminal installed checks the identification using height and color information of object. With the implemented identification function the proposed system sorts the object receiving the privacy protection, implements the monitoring function and provides monitoring and protection function at the same time.     

高频地波雷达风速直接反演的经验模型

利用风浪经验模型从高频地波雷达(HFSWR)的回波谱数据中反演风速需要有效波高等先验信息,因此风速的反演受有效波高反演精度的影响。该文基于风浪经验模型,利用风速和高频地波雷达海面回波二阶谱与一阶谱能量之比的关系,发展了无需波高信息的风速直接反演的经验模型。将风速反演经验模型应用到高频地波雷达风速的反演中,对两部不同频率的雷达在不同海域获得的数据进行了比较分析,结果表明,该文中采用的经验模型能够有效地对风速进行反演,其中三参数模型的结果略好于双参数模型。     

一种双基地雷达探测性能评估的改进方法

一发两收配置下双基地高频地波雷达相对于单基地雷达的优势为提高探测精度和目标截获能力.同时, 双基地高频地波雷达作为一种大型的雷达探测系统, 影响其探测性能的因素众多, 为双基地高频雷达探测性能建立一套有效的评估体系, 对于雷达初期建设与使用过程中的维护与升级, 都具有重要的指导意义.本文结合高频地波雷达和双基地雷达各自特点, 提出了一种基于粒子群算法改进的层次分析法, 克服了传统层次分析法的判断矩阵和一致性检测分离的缺点, 提高了评估方法的可信度与可靠性, 为双基地高频地波雷达探测性能评估提供了一种较为可靠的方法.     

毫米波雷达的应用和发展

描述了毫米波雷达的特点和适用需求,介绍了毫米波雷达在直升机载侦察火控、战场监视、导弹制导、近程防空和星载空间探测方面的应用,探讨了毫米波雷达技术的发展趋势。     

Air traffic control: satellites and artificial intelligence promiseimproved safety and efficiency

Longer-term solutions to air traffic management are examined. These include global networks of satellites for communications, navigation, and surveillance,which may upstage ground radars in the next century. Greater capability in the cockpits (including collision avoidance systems and flight computers with extensive libraries), better weather prediction and information transfer, and plans to artificial intelligence in the system are also reviewed     

Radar Technology Applied to Air Traffic Control

Use of primary radars for air traffic control (ATC) is discussed. The location and the parameters of various ATC radars are described. The clutter environment (land clutter, birds, automobiles, and weather) has had a major impact on the configuration of these radars. Signal-processing techniques and antenna techniques utilized to cope with the clutter are described. Future signal-processing techniques for the ATC radars are postulated.     

无线网络撬装视频监控系统在油田监管中应用的研究

无线网络撬装视频监控系统利用视频压缩、无线传输、远程监控等技术,实现油田管理人员对现场油井运行状况、施工作业进行监控和管理,预防和杜绝现场违章施工或违规操作等现象发生,保证油井现场资产、生产安全。     

Brazil tests world's largest environmental monitoring system

An elaborate environmental monitoring system paid for by Brazil, Sivam was built by the US defense electronics contractor Raytheon Co. (Lexington, Mass.) and two Brazilian outfits, Embraer (Sao Jose dos Campos) and Atech (Sao Paulo)-the former an aeronautics company that has supplied planes for Sivam, the latter the Brazilian system integrator. The US $1.4 billion system pulls together information from over 500 monitoring devices, ranging from satellites to weather balloons covering 5.2 million km/sup 2/ of the Amazon. System headquarters are going up in Brasilia, the nation's capital, and final system tests on the integration of all the network's components are scheduled to begin in October or November, 2003. Sivam is being used to detect illegal logging in Brazil, but can also be used to monitor fires, floods, pollution, weather, and-not least-the status of land set aside for indigenous peoples. The idea is to feed a constant flow of critically important data to scientists and to public authorities responsible for regulating the development and protection of the rain forest that covers 61 percent of Brazil.     

基于ES-ELM和FRFT的高频地波雷达多目标自适应检测

高频地波雷达（high frequency surface wave radar,HFSWR）对于海事监测具有重要的军用及民用意义,然而在HFSWR回波信号中,待检测的目标常常淹没在海杂波和各种背景噪声中.因此,如何有效抑制杂波并实现多目标的自适应检测是HFSWR实现海事检测的关键和难点.该文提出了一种结合误差自校正极限学习机（error self-adjustment extreme learning machine,ES-ELM）和分数阶傅里叶变换（fractional Fourier transform,FRFT）的多目标自适应检测算法.算法根据相空间重构理论获得ELM的最佳状态空间,利用ES-ELM建立海杂波预测模型并对海杂波进行有效抑制;再在分数域根据目标信号的峰值集聚特征,利用Haar-like算子提取目标点的形态特征,并通过ES-ELM神经网络对目标进行自动辨识.实验结果表明,该文提出的算法具有良好的海杂波抑制能力,并可以实现海杂波背景下多运动目标的自适应高精度检测.     

船用导航雷达的技术发展及最新应用

民用船舶是导航雷达的主要市场,成本与性价比需求决定了船用导航雷达与军用雷达大不相同的发展进程。简述了导航雷达市场行情,技术现状与发展趋势,并介绍了导航雷达在安全监视、生态保护等非导航领域的最新应用。     

T/R-R高频地波雷达舰船探测范围分析

基于目标回波和海杂波、大气噪声相对强度,理论分析及仿真研究了T/R-R高频地波雷达系统对舰船目标探测范围。分别分析了单基地(T/R)、双基地(T-R)高频地波雷达方程;基于T/R、T-R雷达系统海杂波理论模型,仿真了高频地波雷达一、二阶海杂波谱;提出了计算加权平均信杂比方法,从信杂比的角度分别确定T/R、T-R高频地波雷达系统的探测范围,T/R-R高频地波雷达系统的探测范围为T/R和T-R系统探测范围的组合。     

一种L 波段40 kW 固态发射机的设计

介绍了一种L 波段40 kW 固态发射机的系统设计,阐述了发射机射频链路、监控保护等各部分的设计特点和实现方法,介绍了针对航管雷达高可靠性的使用要求所采用的技术,以及解决发射机监控系统电磁干扰等问题所采取的措施。该发射机的成功研制,可为后续新一代航管一次雷达固态发射机设计提供参考。     

12-kW S-band solid-state transmitter for modern radar systems

The development of a 12-kW solid-state transmitter, operating over 2.7-2.9 GHz, for use in modern surveillance and air-traffic control radars, is described. 12 kW of peak power with a pulse width of 100 μs and a duty cycle of 10% is achieved by combining 56 300-W high-power solid-state amplifiers. Other key performance parameters are pulse-to-pulse stability (moving-target-indication improvement factor >90 dB), MTBF (mean time between failures) >22,000 h, instantaneous and width of 200 MHz, extremely high pulse fidelity, and self-pulsing low-voltage operation for high efficiency     

炮兵雷达的体系与发展

炮兵雷达是一个装备概念,包括野战炮兵使用的防空兵雷达、战场侦察、雷达和炮兵作战时所需的各种辅雷达,炮兵雷达的体系结构是探讨炮兵雷达分类、组成、性能、功能、使用、发展等问题,本文主要论述炮兵战场目标侦察雷达、炮兵侦校雷达和对海侦校雷达的体系结构,重点放在炮兵雷达的发展。