星载InSAR均匀相位构形的空间基线稳定性

星载InSAR(干涉式合成孔径雷达)在对地观测任务中具有广泛的应用,其空间基线随卫星编队平台的运动而变化。本文基于卫星编队的构形原理,定义了星载InSAR均匀相位构形。根据干涉测量原理定义了相关基线及其稳定度,研究了不同均匀相位构形下星载InSAR的基线稳定性。     

Electronic warfare in the optical band: Main features,examples and selected measurement data

The paper presents the possibilities of, and methods for, acquiring, analysing and processing optical signals in order to recognise, identify and counteract threats on the contemporary battleground. The main ways electronic warfare is waged in the optical band of the electromagnetic wave spectrum have been formulated, including the acquisition of optical emitter signatures, as well as ultraviolet (UV) and thermal (IR) signatures. The physical parameters and values describing the emission of laser radiation are discussed, including their importance in terms of creating optical signatures. Moreover, it has been shown that in the transformation of optical signals into signatures, only their spectral and temporal parameters can be applied. This was confirmed in experimental part of the paper, which includes our own measurements of spectral and temporal emission characteristics for three types of binocular laser rangefinders. It has been further shown that through simple registration and quick analysis involving comparison of emission time parameters in the case of UV signatures in “solar-blind” band, various events can be identified quickly and faultlessly. The same is true for IR signatures, where the amplitudes of the recorded signal for several wavelengths are compared. This was confirmed experimentally for UV signatures by registering and then analyzing signals from several events during military exercises at a training ground, namely Rocket Propelled Grenade (RPG) launches and explosions after hitting targets, trinitrotoluene (TNT) explosions, firing armour-piercing, fin-stabilised, discarding sabots (APFSDS) or high explosive (HE) projectiles. The final section describes a proposed model database of emitters, created as a result of analysing and transforming the recorded signals into optical signatures.     

武装直升机微光电视瞄准原理分析

主要就某型武装直升机加装微光电视瞄准系统后,在分析了该系统的关键硬件组成、软件设计、微光电视图像信号的增强技术、控制器设计和信号交联的基础上,研究了夜视设备与机载武器的兼容性问题。即:如何与机载瞄准具进行匹配实现对目标的跟踪瞄准。     

目标反射特性对激光末制导精度的影响

从物理光学和辐射原理的角度分析了目标反射特性对激光末制导精度的影响 ,给出了目标反射系数的直接测量方法 ,最后得出结论并提出了减少受其影响的措施。分析结果表明目标反射特性会影响激光末制导炮弹的接收反射激光信号功率的大小 ,进而影响激光末制导炮弹的制导概率 ,因而对于不同质地的目标 ,要根据目标的反射系数来确定激光指示器可靠的照射距离 ,选择其照射攻击部位 ,以提高激光末制导精度。     

激光推进发动机与激光发射弹道主要参数分析

激光推进是一种应用前景广阔的先进推进技术。讨论了激光推进发动机性能参数,飞行器在无大气阻力并忽略地球曲率和自转条件下发射与入轨所要求的最佳比冲,激光平均功率与电网能量消耗等问题。指出用激光发射微小卫星可以得到高质量比,激光推进发动机最优的比冲为12 240m/s。     

激光陀螺数字抖动控制方法与特性

针对传统的模拟抖动控制系统体积大、灵活性差的缺点,设计了一种基于单片机的新的激光陀螺数字抖动控制方法,建立了陀螺抖动的数学模型,比较研究了传统的模拟正弦波驱动和新的数字方波驱动的抖动特性,指出了后者不同于前者的抖幅变化律及非线性的随机噪声注入方式。仿真和实验证明,该方法能很好满足激光陀螺抖动控制要求,保证陀螺性能。     

Supplier‐buyer contracting: Asymmetric cost information and cutoff level policy for buyer participation

We consider the problem of designing a contract to maximize the supplier's profit in a one‐supplier–one‐buyer relationship for a short‐life‐cycle product. Demand for the finished product is stochastic and price‐sensitive, and only its probability distribution is known when the supply contract is written. When the supplier has complete information on the marginal cost of the buyer, we show that several simple contracts can induce the buyer to choose order quantity that attains the single firm profit maximizing solution, resulting in the maximum possible profit for the supplier. When the marginal cost of the buyer is private information, we show that it is no longer possible to achieve the single firm solution. In this case, the optimal order quantity is always smaller while the optimal sale price of the finished product is higher than the single firm solution. The supplier's profit is lowered while that of the buyer is improved. Moreover, a buyer who has a lower marginal cost will extract more profit from the supplier. Under the optimal contract, the supplier employs a cutoff level policy on the buyer's marginal cost to determine whether the buyer should be induced to sign the contract. We characterize the optimal cutoff level and show how it depends on the parameters of the problem. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 41–64, 2001     

舰载烟幕弹的最佳使用时机

针对激光制导反舰导弹的作战使用过程 ,依据侦察探测的倒立方律及对导弹的捕捉概率 ,探讨舰载烟幕弹的最佳使用时机问题 ,指出应充分利用舰艇 C3I系统的综合信息 ,由舰指挥员负责实施     

平板湍流边界层内气泡流流动实验研究

在低湍流度水槽里 ,利用片光源显示了平板气液两相湍流边界层内气泡流的流场结构 ,研究了平板安装位置、来流速度、喷气方式等参数对湍流边界层内气泡流的影响 .利用激光测速技术测量了平板水平放置时气泡流最外缘处的水平速度及厚度 .结果表明 :平板喷气减阻的原因在于喷气改变了平板湍流边界层的流动结构 ,抑制了湍流     

亚音速轴流风扇静转子相互作用线谱噪声预报

静转子相互作用线谱噪声是亚音速轴流风扇主要噪声源之一,快速预报该噪声对风扇设计初期的叶片选型和参数设计具有重要意义.因此在叶栅响应函数理论的基础上考虑静转子叶片的相互作用,采用叶片经验尾流模型模拟转子尾流,推导得到静转子叶栅相互作用线谱辐射声功率半经验半理论计算公式.通过与NASA已有的试验模型和计算模型结果对比,验证...