半仿真方位高分辨后置处理方法

MVDR自适应波束形成可获得良好的目标方位估计性能,但其方位分辨力仍受限于阵列孔径.为进一步提高目标方位分辨性能,在MVDR自适应波束输出的基础上,提出了一种高分辨后置处理方法.在两目标方位不可分时,仿真构造两个目标的阵列输出空间方位谱,通过搜索两目标的方位和幅值,与真实数据的空间方位谱输出作匹配处理,从而获得目标的方位估计.实验室仿真及海试数据处理验证了该方法的有效性.     

电离层不规则体对P波段星载SAR成像的影响

电离层不规则体导致星载合成孔径雷达（SAR）信号产生幅度及相位闪烁,严重影响低波段星载SAR的图像分辨性能。推导了具有普遍性的幂律谱对应的双频双点互相关函数。基于此研究了电离层对星载P波段SAR分辨性能的影响及其规律。研究表明,电离层不规则体导致星载P波段SAR两维分辨率恶化,图像峰值增益损失严重。电离层不规则体强度,谱指数,外尺度等参数的增大都会导致星载SAR图像分辨率及峰值增益进一步下降。基于相位屏技术的数值仿真结果验证了本文研究。     

新疆石河子内初班学生的学习适应性研究

为深入了解内初班学生的学习适应性状况,本研究分别在石河子市四所内初班承办学校中,严格按照分层抽样的方法选取了294名学生作为被试,采用《学习适应性测验》量表探求内初班学生的学习适应性特征。结果显示:石河子内初班学生的学习适应性与全国常模基本一致,学习适应不良主要集中在学习技术和学习态度上。在性别上、年级上差异不显著,民考民和民考汉学生的学习适应性在全量表上差异显著,总体上民考民学生的学习适应性优于民考汉学生。     

近程舰炮武器系统拦截高速目标发展研究

反舰导弹的超声速特性使得现役近程舰炮武器系统的反应时间严重不足,毁伤能力明显下降.针对高速目标,分析了目标对系统的随动性能需求,研究了系统情报处理、传感器捕获跟踪及火控解算等时间特征参数、及系统毁伤能力,并提出了解决问题的初步想法.分析结果表明,可以提高近程舰炮武器系统对超高声速目标的跟踪毁伤能力,实现对该类目标的有效拦截.     

Tuning the reactivity of Al–Ni by fine coating of halogen-containing energetic composites

In this paper, various core-shell structured Al–Ni@ECs composites have been prepared by a spray-drying technique. The involved ECs refer to the energetic composites (ECs) of ammonium perchlorate/nitrocellulose (AP/NC, NA) and polyvinylidene fluoride/hexanitrohexaazaisowurtzitane (PVDF/CL-20, PC). Two Al–Ni mixtures were prepared at atomic ratios of 1:1 and 1:3 and named as Al/Ni and Al/3Ni, respectively. The thermal reactivity and combustion behaviors of Al–Ni@ECs composites have been comprehensively investigated. Results showed that the reactivity and combustion performance of Al–Ni could be enhanced by introducing both NA and PC energetic composites. Among which the Al/Ni@NA composite exhibited higher reactivity and improved combustion performance. The measured flame propagation rate (v = 20.6 mm/s), average combustion wave temperature (T_max = 1567.0 °C) and maximum temperature rise rate (γ_t = 1633.6 °C/s) of Al/Ni@NA are higher than that of the Al/Ni (v = 15.8 mm/s, T_max = 858.0 °C, and γ_t = 143.5 °C/s). The enhancement in combustion properties could be due to presence of the acidic gaseous products from ECs, which could etch the Al₂O₃ shell on the surface of Al particles, and make the inner active Al to be easier transported, so that an intimate and faster intermetallic reaction between Al and Ni would be realized. Furthermore, the morphologies and chemical compositions of the condensed combustion products (CCPs) of Al–Ni@ECs composites were found to be different depending on the types of ECs. The compositions of CCPs are dominated with the Al–Ni intermetallics, combining with a trace amount of Al₅O₆N and Al₂O₃.     

One-bit splitting deceptive jamming against SAR

One-bit quantization is a promising technique due to its performance retention and complexity reduction in a deceptive jammer against synthetic aperture radar (SAR). In this paper, the 1-bit quantization technology is utilized to agilely generate split false targets in the SAR imagery once the radar signal is intercepted, which reduces the complexity of the jammer significantly with guaranteed focusing quality. A single-frequency threshold is used to decompose harmonics incurred by the 1-bit quantization, and its parameters are adjusted through different pulse repetition intervals to provide steerable modulations. In this way, the SAR signal is split into coupled false scatterers during the 1-bit interception. By further deploying amplitude, time-delay, and Doppler frequency modulations on the 1-bit intercepted signal, the split false targets are created. The proposed approach is compared with different deceptive jamming methods to show its validity in effectiveness and cost, and numerical experiments are also presented for verification.     

基于波束域MUSIC方法的高分辨方位估计

现代声纳系统普遍采用水听器基阵和一定的信号处理来提高对目标的检测和定位能力,而基阵的波束形成则在其中起着核心作用。文中研究了窄带波束域高分辨方位估计技术,分析了波束域MUSIC方位估计的构造过程和具体实现方法。仿真计算表明,基于波束域MUSIC的方位估计算法是一种分辨空间小角域内多个目标的有效方法。     

FAE野外空中爆炸效应实验研究及其一次起爆机理探讨

野外进行1．8kg的FAE静爆实验,采用不同配方的纯固态燃料和液一固混合燃料与等质量的TNT对比分析。实验结果表明,FAE的爆炸效果明显优于等质量的TNT,而纯固态FAE爆炸性能强于液一固混合FAE;FAE爆炸后测到的超压分布呈现单调减趋势,这是由于测量点都分布在云爆区范围之外;FAE的云雾分散效果优于等质量的TNT装药,火焰持续时间也长。通过高速摄影图片看出,合适配方的纯固态无约束的FAE弹体火球的持续时间与有约束的液一固混合FAE弹体相当。分析了纯固态FAE爆炸后超压峰值时刻与火球最大直径时刻不同步的原因,探讨了纯固态FAE一次起爆机理。     

高机动性能导弹大迎角测量方法研究

简要介绍了嵌入式大气数据传感系统的概念及技术。针对高速高机动性能导弹大迎角高马赫飞行的特点,提出应用嵌入式大气数据传感技术解决导弹大迎角测量问题,并结合导弹自身特点,给出了迎角测量原理和方法,这对于新型导弹的设计具有一定的借鉴意义。     

高频地波雷达目标高度估计的AR模型方法

高度估计对于高频地波雷获取三维信息、提高预警能力很有意义。然而目标RCS的随机起伏对高度估计产生严重影响,通过对RCS随机起伏的AR模型建模和模型参数的自适应估计,提出了在RCS变化的条件下高度估计的扩展卡尔曼滤波算法。通过Monte Carlo仿真和外场试验数据的处理,验证了该方法对抑制RCS随机起伏、提高高度估计精度的有效性。