信标模式机动目标跟踪数据实时处理

信标模式下的机动目标测速数据存在较大时变系统误差, 导致目标飞行弹道解算精度降低. 针对此问题, 本文通过增加表征系统误差的分量项, 对机动目标运动模型的状态向量扩维, 并将系统误差引入到测量方程中, 提出一种弹道估计新算法. 利用无迹卡尔曼滤波计算跟踪目标的轨迹, 同时估计系统误差. 仿真试验表明, 该方法无论在应答或信标模式下都可以解算出满足精度要求的弹道.     

Microstructure characterization and compressive performance of 3D needle-punched C/C–SiC composites fabricated by gaseous silicon infiltration

3D needle-punched C/C-SiC composites were fabricated from carbon fiber reinforced carbon (C/C) preforms, with densities of 1.05?g/cm³ and 1.28?g/cm³, by the gaseous silicon infiltration (GSI) method at fabrication temperatures from 1500?°C to 1800?°C. The compressive strengths and elastic moduli in transverse direction are larger than those measured under longitudinal compression except that samples fabricated from 1.28?g/cm³ density exhibit lower elastic moduli in transverse direction than in longitudinal direction. The compressive strength and modulus increase with fabrication temperature at 1500?°C and 1600?°C, and then decrease with higher fabrication temperature. Samples fabricated from the lower density C/C preforms have greater compressive strength and modulus. X-ray tomography was applied before and after the mechanical tests to characterize the microstructure and damage patterns, and the results indicated that for C/C-SiC composites fabricated at 1700?°C from 1.28?g/cm³ density C/C preform the matrix has a volume fraction (vol%) of 36.9%, and the initial intra-bundle cracks (0.6?vol%) display a space crossing structure while the inter-bundle pores (6.0?vol%) are special irregularly distributed.     

Hysteresis loops of carbon fiber-reinforced ceramic-matrix composites with different fiber preforms

The hysteresis loops of C/SiC ceramic-matrix composites (CMCs) with different fiber preforms, i.e., unidirectional, cross-ply, 2D and 2.5D woven, 3D braided, and 3D needled at room temperature have been investigated. Based on fiber slipping mechanisms, the hysteresis loops models considering different interface slip cases have been developed. The effects of fiber volume fraction, matrix cracking density, interface shear stress, interface debonded energy, and fibers failure on hysteresis loops, hysteresis dissipated energy, hysteresis width, and hysteresis modulus have been analyzed. An effective coefficient of fiber volume fraction along the loading direction (ECFL) was introduced to describe fiber preforms. The hysteresis loops, hysteresis dissipated energy and hysteresis modulus of unidirectional, cross-ply, 2D and 2.5D woven, 3D braided and 3D needled C/SiC composites have been predicted.     

基于Turbo协同分集的通信方案的性能仿真

本文基于Turbo码和协同通信的相关理论,提出一种新的基于Turbo协同分集的协同通信方案。在加性高斯白噪声和瑞利快衰落的两种信道条件下的仿真结果表明,基于Turbo协同分集的协同通信方案比现有的基于Turbo编码的协同通信方案具有更优的误比特率性能。     

基于VLL技术的跨网络接入设计

企业使用VPN（VirtualPrivateNetwork,虚拟专用网）安全灵活的通过已建成的网络或Intemet连接分支,但VPN技术繁多,优点各有不同,本文深入研究了VLL（VirtualLeasedLine）技术,为VLL技术在企业网中的应用提供参考。     

离散化绝对值大于1的定点数

论述把一个绝对值大于１的定点数拆分成用有限个贮存单元表示的离散数据的方法，并在文中所述特殊情况下，给出了数值转换求权系数的公式。     

星间链路地面管理设备多阵面相控阵保护机制

多阵面相控阵星间链路管理设备既解决了传统星间链路设备卫星与地面站间精密测量和数传、全球系统的自主导航功能的问题,又缓解了地面星间链路管理设备不能满足“北斗”全球系统部署的困难。分析了多阵面相控阵星间管理设备的特点,讨论了多相控阵同时工作下阵面保护的难题,提出了天线设计与波束管理软件控制两种方法相结合的解决方案。     

新型武器装备战斗力快速生成的途径研究

针对在研和进场初期新型武器装备暴露出来的风险,自立项开始,依据科研程序,紧紧抓住质量问题,有序的开展各阶段、各系统、各环节的研制工作,提出寻找最佳人机结合途径,达到解决问题,使新型武器装备以最短的过渡期快速生成战斗力的目的。     

基于目标模型的激光主动成像仿真

成像仿真可为激光主动成像系统的优化设计提供参考,为目标探测和识别算法研究奠定数据基础。针对空间目标探测,提出了基于目标模型的激光主动成像仿真方法,介绍了对距离选通激光主动成像过程进行全数字仿真的主要步骤。通过对比分析,验证了仿真方法的有效性。     

基于态势的高频雷达频率评估技术

提出一种高效的工作频率评估技术,通过双向自动映射,在规划和探测过程中对雷达波位的工作频率进行预先或实时评估,帮助用户提供操作参考。通过对工作频率评估技术的应用验证,该技术能自动及时提供工作频率评估结果,提高了人机交互效率,促进了雷达探测性能的提升。