基于红外辐射信息的IRST系统机动目标跟踪算法

传统的IRST(红外搜索与跟踪)系统是一个仅有角测量的系统,对于目标距离是不可观测的。文中增加了红外探测器对目标红外辐射的响应信息这一测量项,使其成为一个距离可观测系统,并在此基础上,建立了目标的观测模型,推导出了机动目标跟踪的EKF跟踪算法。通过跟踪一个机动目标的仿真过程,对算法性能进行了检验,结果表明：本算法对机动目标能进行有效的跟踪,而且跟踪精度也是令人满意的。     

利用小波、匹配子空间探测器和图像配准技术探测红外小目标

红外传感器和先进的信号处理技术已被用以探测具有严重杂波和噪声的环境中的小目标(或者点状目标)。本文讨论子波探测算法和处于杂波环境中的小目标跟踪技术。同时也讨论一种基于光学通量估计值的新的配准算法和用以探测机动小目标的匹配子空间探测器。两种探测器都引用了自适应恒定虚警率探测统计法。文中还简单介绍了用无类别数据库以及目标直升机和装有视频摄像机的平台对探测和跟踪算法进行的模拟。     

空域机动目标智能搜索跟踪算法

为在低对比度低信噪比的条件下精确快速搜索跟踪空域机动目标,提出一种智能电视搜索跟踪算法。采用金字塔波门方法进行搜索,搜索区域大小逐级缩小,采用自递归OTSU对图像进行分割,再用连通域分析和灰度级门限判定检测目标,统计目标出现的概率,确定最优目标;锁定最优目标进入跟踪状态,可根据目标尺寸自适应的调整波门大小,对目标瞬时遮挡的情况采用综合预测得到目标位置,若不满足目标灰度级门限判定或预测条件,则转为重新搜索,实现无人工干预的智能搜索跟踪功能。实验结果表明,在DM642平台上搜索状态下最大区域的搜索时间小于20ms,在跟踪状态下目标识别时间小于5ms。完全满足现代空域机动目标电视智能跟踪系统速度、精度和稳定性的要求。     

基于PQ法的惯性/光机复合指向控制方法

为了进一步提升机动平台的遥感侦查能力,在惯性稳定平台的基础上,结合光电探测信息通路中的快速反射镜,构成惯性/光机复合指向系统,借助快返镜的快速运动补偿惯性稳定回路的伺服误差,可有效提高探测光轴的稳定精度与指向跟踪的机动性能。将惯性稳定回路与快反镜控制回路转化为平行的双入单出系统,针对两者作用频带与作动范围的差异,提出一种惯性/光机复合指向控制方法,解决系统中惯性稳定机架指向与快反镜指向叠加的稳定性匹配和频带分解问题,从而提升光轴的稳定精度和机动性能。仿真结果表明:加入了快反镜的惯性稳定平台的误差有显著减小,其跟踪误差量从0.018减小到0.005以内,验证了控制器设计的有效性。     

随动式车载光电搜跟系统研究

为满足武器系统外场试验对目标、背景及干扰的数据采集及其它制导系统的性能验证,本文设计了一种随动式车载光电搜跟系统.利用光学跟踪平台实现对动态目标的搜索和跟踪,同时控制车载转台随动,车载转台可搭载导引头等其它光学探测设备,提高了系统的负载能力.针对系统延时带来的跟踪误差,采用卡尔曼滤波算法对目标位置进行预测.试验结果表明,加入预测算法后,跟踪平台运动更加平稳,跟踪精度得到提高.针对设备间由于坐标不一致及安装精度和零位偏差带来随动误差,通过位置补偿对随动控制指令进行修正,改善了随动观测精度.系统采用模块化设计,可靠性高,可用于武器系统的外场试验.     

球载雷达与红外联合探测系统研究

针对球载预警探测装备的应用需求,探讨了在系留气球平台实现雷达与红外联合探测系统的意义;研究了雷达与红外联合探测信息融合的处理流程,包括搜索与跟踪和联合目标分类与识别的处理流程,提供了基于点迹、航迹的搜索与跟踪融合处理算法;构建了外场试验系统,开展了搜索与跟踪融合处理算法的系统检验,验证了雷达与红外联合探测系统对目标探测精度和跟踪稳定性提高的有效性。试验结果表明,雷达与红外联合探测系统可提高球载预警探测系统的作战效能。     

凝视型海上红外搜索与跟踪系统(上)

英国QinetiQ公司为英国国防部研制了一种海上红外搜索与跟踪(IRST)演示器。该系统使用两台凝视型红外摄像机以及能够分裂视场的光具以便对地平线进行全景跟踪。同现有的扫描型红外搜索与跟踪系统相比,使用凝视型探测器的红外搜索与跟踪系统具有更高的灵敏度和追踪速率。演示器配备的是已成商品的640×512元中波红外探测器,但它在将来也可接纳1024×768元的探测器。演示系统装有一种特殊的可变换滤光片以便根据主要的环境状况选择最佳的工作波段,并装有一种光束转向器以利于非均匀性校正和图像的稳定。利用现场可编程门列阵(FPGA)和用于探测和跟踪的PowerPC硬件,演示系统已实现了实时数据处理。本文描述凝视型海上红外搜索与跟踪系统并介绍其一些输出图像。     

超宽温折衍混合红外搜索跟踪光学系统设计

为满足红外搜索跟踪成像系统的环境适应性的特殊要求,设计了一种用于搜索跟踪的红外超宽温成像系统,其工作波段为3.7~4.8μm,视场角为11.42°。该系统采用三片式结构,使用锗和硅两种红外材料,引入两个非球面和一个衍射面,使系统具有结构简单、体积小、重量轻、成本低等优点。设计结果表明;该系统在-80~160℃温度范围内成像质量接近衍射极限,适用于像元尺寸为30μm、像元数为320×240的焦平面阵列探测器,保证了红外搜索跟踪系统在超宽温度下稳定的工作性能,对该系统的探测距离进行了估算,系统能够探测1.0 km处的目标。     

点源目标的红外搜索与跟踪系统的作用距离估算

红外目标的探测在告警、制导等领域具有重要意义.在中远距离探测中,红外搜索与跟踪系统的作用距离受到大气传输、红外探测器的性能以及目标的辐射功率等因素的影响.传统红外系统的作用距离方程具有一定的局限性.考虑到目标成像弥散斑和背景辐射的影响,对红外搜索与跟踪系统(IRST)的作用距离方程进行修正,得到IRST系统的作用距离与系统的噪声等效温差(NETD)之间的关系,推导出探测器噪声限下对点源目标的作用距离方程.为IRST系统的综合评估和设计提供了一个重要的依据.     

IRST系统搜索扫描速率对探测距离的影响

在搜索状态下的探测距离是搜索跟踪系统的重要性能指标。从搜索状态下系统探测器能量积分的过程进行理论分析,得到了系统扫描速率与系统探测距离之间的关系,导出了扫描速率对IRST系统探测距离影响的关系方程。为IRST系统的综合评估和设计提供了一个重要的依据。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.