信息战条件下敌我识别技术研究

敌我识别是高技术条件下现代战场中自动目标识别技术的重要应用之一.高科技条件下现代战场中的敌我目标识别问题,一直是国际雷达领域和信息处理技术的主攻方向.系统地介绍了敌我识别系统的工作原理,分析了敌我识别系统的工作模式,给出了基于贝叶斯原理的目标综合识别方法,并将贝叶斯目标属性识别算法应用于敌我目标综合识别系统中,实现了信息战条件下对敌我目标的属性判别.     

二次雷达射频接收的应用

二次雷达是识别雷达所发现目标的敌我属性的电子设备,主要用于军事监测和打击,装备在飞机、舰艇、坦克和雷达站的询问机或问答机,组成合作式的目标敌我识别系统。本文介绍增强型舰载识别器,该识别器扩大了识别目标的信息范围,提高了识别目标的可靠性、保密性和抗干扰性能等。     

雷达敌我识别干扰方法研究

雷达敌我识别系统用来识别雷达发现目标的敌我属性,它的基本原理是询问机发射射频脉冲询问信号给应答机,应答机收到后自动发回应答信号完成敌我识别;雷达敌我识别干扰则是利用己方的雷达敌我识别对抗装备对敌方的雷达敌我识别系统实施电子干扰的作战行动。文章通过阐述基本工作原理、分析典型信号特征,介绍了雷达敌我识别系统;针对其存在的弱点,分析了雷达敌我识别干扰的可行性;结合已有研究成果和可行性分析,探讨了压制性干扰、欺骗性干扰和灵巧干扰的方法,对雷达敌我识别对抗技术的深入研究具有一定的意义。     

雷达敌我识别系统及其对抗技术研究

敌我识别（Identification，Friend or Foe，IFF）系统在现代战争中占有极为重要的地位。本文介绍了雷达敌我识别系统的工作原理和工作模式，分析了雷达敌我识别系统所面临的威胁，并对雷达敌我识别系统对抗技术进行了初步探讨。     

外军飞机对海目标敌我识别错误机理分析

海战场环境下受复杂识别链路时序关系及海面复杂电磁传播环境影响,飞机时常错误识别海上目标的敌我属性,带来误击事件发生隐患.以北约敌我识别系统Mark XII为研究对象,分析了飞机识别海上目标敌我属性技术机理和信号链路流程,给出了不同链路情况下的敌我识别结果,从系统本身、自然环境、电子对抗等角度对识别错误机理进行了分析.研究结论可为我国空海敌我识别能力的提升提供借鉴,也可为开展国外敌我识别系统电子对抗提供有效支撑.     

针对敌我识别系统的个体识别研究

对敌我识别系统的研究大部分集中在对其信号的检测和解调上，对辐射源个体识别技术也是近年来的研究热点，但很少有专门针对敌我识别系统的个体识别研究。本文通过分析敌我识别信号，发现其区别于普通雷达信号的主要两个特点：一是信号载频固定不变；二是信号以码字为单位出现，且脉冲时序格式固定。针对敌我识别信号的这两个特点，本文设计的个体识别方法重点包括：一、瞬时频率可作为有效的个体特征；二、可综合同一串码字里多个脉冲的个体识别结果，提高目标个体识别正确率。试验结果显示，相较于只用单脉冲的方法，本文算法的个体识别正确率更高。     

雷达询问敌我识别技术

主要从雷达敌我识别综合系统的必要性、实现雷达敌我识别综合系统的可能性、ＲＩＳＳ系统中敌我识别应答机、毫米波敌我识别、非协同目标识别等几方面论述了雷达询问敌我识别技术以及综合化问题。     

二次雷达敌我识别器系统识别概率的探讨

本文定义了几种二次雷达协同目标检测概率,指出了影响系统识别概率的主要因素,提出了二次雷达敌我识别器系统识别概率只能通过系统试验进行评估,设备出厂验收时,只测量一次询问的目标检测概率。     

《电讯技术》专题资料 《现代战争目标识别技术的现状及发展》题要(二)

超视距雷达的舰船目标识别技术探讨传统的敌我识别系统都只能在视距内工作 ,而高频地波和天波雷达、微波超视距雷达均可探测到视距外的海上目标 ,但目标的属性识别问题一直是它们的难点 ;本文针对超视距雷达的技术特点 ,对有关的舰船目标识别方法进行了探讨。非协同目标识别的相关技术目标识别是雷达发展过程中的一个重大研究课题 ,而非协同目标识别更是当今最为活跃的研究领域。本文对非协同目标识别的概念及其相关技术进行了介绍和简要分析。基于多传感器数据融合的非协同目标识别文中介绍了多传感器数据融合的概念 ,数据融合应用于非协同…     

信息战条件下敌我目标综合识别方法研究

介绍了国外敌我目标识别的现状及发展趋势,提出了信息战条件下应采用综合识别系统解决目标敌我识别问题的建议。最后举例说明Bayes目标属性识别算法在综合识别系统中的具体应用。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Call for Papers

正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its