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.     

耦合杀伤区射击次数与舰艇间距分析

研究了舰艇编队协同防空中满足一阶耦合杀伤区对来袭目标射击次数要求的编队舰舰间距配置问题。依据耦合杀伤区的概念,运用几何三角关系和解析法分析了一阶和二阶耦合杀伤区的纵深计算方法。并对给定杀伤区纵深的单舰和协同舰射击次数进行了研究,给出了射击次数模型及受目标投弹圈影响的耦合杀伤区纵深约束条件。对不同入射舷角的目标、不同速度的导弹类目标和不同高度、速度的飞机类目标3种情况下的射击次数与间距关系进行了仿真,得到了一些有益的结论,对编队近程防空队形的间距配置具有指导意义。     

热推力器层板换热芯流固耦合传热与流动仿真

热推进技术采用小分子量气体作为推进剂可以获取较高的比冲,是具有巨大应用前景的空间推进技术,而提高热推力器换热芯换热效率是目前亟待解决的问题。本文设计了基于层板结构的换热芯,结合层板结构的传热特点与流固耦合传热理论,对层板换热芯传热和工质流动进行了模拟计算。根据耦合传热理论,将层板与工质的导热简化为系统内部边界条件,通过仿真计算得到了层板流固耦合温度场和流场分布特性,工质可以被加热至2300K以上,验证了层板结构用于热推力器换热芯的有效性。     

新型双向流量计流固参数特性仿真及试验

导磁体小球的受力平衡特性直接影响到新型双向流量计的测量精度。为了研究导磁体小球在同轴环形轨道中运行的平衡性及流体密度和导磁体几何参数对其运动平衡性的影响,首先通过理论分析了同轴环面流道内导磁体小球在旋转轨道内的运动平衡性条件并建立了流固耦合模型,然后采用 Ansys workbench 中的最优化算法根据小球平衡条件进行小球运动平衡特性仿真,再根据样机进行小球平衡性实验研究,最后进行了被测液体密度变化和小球半径变化对小球运动平衡性影响的仿真分析。结果表明：小球运行平衡转速随流体密度增大而增大,也随小球半径的增大而增大。     

非线性耦合反应扩散系统解的存在性与脉冲同步

研究了耦合反应扩散系统整体解的存在性,并对其进行了证明。在此基础上,进一步加入脉冲条件,首次提出该系统脉冲同步的稳定性准则,得出脉冲误差系统是全局拟吸引的结论。