导波雷达液位计检测单元的研究与设计

针对现代工业的测量要求,提出了一种导波雷达液位计的硬件设计方案。考虑到液位测量死区比较小、测量精度比较高,且安装环境比较恶劣等因素,采用超宽带雷达脉冲作为脉冲发射源,并以双杆作为传播介质。同时,为了解决因传播距离比较短而造成的测量时间和回波幅值较小这一问题,引入了基于等效时间采样和相干测量方法的接收系统。仿真结果表明,该设计可用于导波雷达液位计,满足测量要求,并具有良好的性能。     

对预警探测雷达模拟器目标分辨率模型的校验方法的研究

预警探测雷达模拟器目标分辨率设置会影响目标数量的探测,分辨率错误会产生与实体雷达不一致的虚警和漏警,影响预警探测雷达模拟器的逼真度。本文首先从理论上分析了对目标分辨率模型进行校核应该注意的几个方面,然后研究了用来测试验证目标分辨率模型的空情想定的设计方法,通过对预警探测雷达模拟器目标分辨率模型进行校验,可以有效提高模型的仿真效果。     

基于串行雪崩纳秒脉冲源的设计

高能量瞬时脉冲的产生及测量一直是探测领域内的研究热点.文中结合雪崩三极管的最大雪崩电流,设计了基于单级雪崩三极管串行级联的窄脉冲产生电路,用衰减器配合泰克P6139A探头,测得脉冲为单极性波,峰峰值可达750V,半高宽3.4ns,可重复频率达10kHz,波形稳定性好.脉冲源电路具有硬件简单、性能稳定、易于匹配等优点,可用于低频段脉冲探地雷达系统.     

基于脉冲幅度特性的相控阵雷达识别技术研究

为有效识别相控阵雷达,提出了一种基于截获脉冲幅度特性分析的识别方法。该方法根据相控阵雷达与常规机械扫描雷达的扫描方式存在很大差异的特点,建立侦察设备截获脉冲的幅度模型,并通过仿真得到不同体制雷达被截获的脉冲幅度特性。求得不同体制雷达被截获的脉冲序列幅度特性与正弦序列幅度特性的相似系数,以此为依据来识别相控阵雷达。通过比较实验证明了该方法的有效性。     

基于DRFM的脉冲多普勒雷达组合干扰及其效能评估

脉冲多普勒雷达具有较强的抗干扰能力，对其实施有效干扰有一定的困难。本文仿真研究了两种基于数字射频存储器的脉冲多普勒雷达组合干扰技术，并分别提出了脉冲多普勒雷达压制性干扰和欺骗性干扰的干扰效果度量方法，该方法在具体应用场合更贴近于干扰抗干扰的动态对抗过程。     

探地雷达回波信号的特征提取和分类

探地雷达的回波信号具有非平稳特征.为实现非平稳信号的检测和分类,采用了二进小波变换、主分量分析与Fisher线性判别分析和前馈多层感知器分类器分别对探地雷达回波信号进行小波分解、去相关与特征选择和分类.实验结果表明,该算法具有很好的分类效果.     

Removal of bird-contaminated wind profiler data based on neural networks

This paper presents the results of a study that relied on trainable neural network classifiers to identify and remove bird-contaminated data from wind measurements recorded by a 1290-MHz wind profiler. A wind profiler is a Doppler radar system measuring the three-dimensional wind field. Migrating birds crossing the radar beam can lead to erroneous wind observations. Bird removal was performed by training conventional feedforward neural networks (FFNNs) and quantum neural networks (QNNs) to identify and remove bird-contaminated data recorded by a 1290-MHz wind profiler. A series of experiments evaluated several sets of input features extracted from wind profiler data, various FFNNs and QNNs of different sizes, and criteria employed for identifying birds in wind profiler data.     

Stochastic models for recognition of occluded targets

Recognition of occluded objects in synthetic aperture radar (SAR) images is a significant problem for automatic target recognition. Stochastic models provide some attractive features for pattern matching and recognition under partial occlusion and noise. In this paper, we present a hidden Markov modeling based approach for recognizing objects in SAR images. We identify the peculiar characteristics of SAR sensors and using these characteristics we develop feature based multiple models for a given SAR image of an object. The models exploiting the relative geometry of feature locations or the amplitude of SAR radar return are based on sequentialization of scattering centers extracted from SAR images. In order to improve performance we integrate these models synergistically using their probabilistic estimates for recognition of a particular target at a specific azimuth. Experimental results are presented using both synthetic and real SAR images.     

基于混沌的雷达网信息加密方法

解决情报传输安全的主要方法是对情报加密。论文首先介绍了一种基于一维logistic方程的情报加密方法,并给出了相应的实现算法,然后将该方法用于雷达情报自动化系统进行了仿真,仿真结果表明该算法可行有效,最后讨论了该方法的优点和进一步研究的方向。     

基于FRFT的线性调频信号映射方法的快速算法

针对基于分数傅立叶变换(Fractional Fourier transform，FRFT)的线性调频信号(LFM)的参数估计方法，提出了基于Radon变换的判决准则，并建立了相应的快速算法。该映射方法将具有同样调频斜率、同样多普勒中心频率、不同初始相位的信号映射到同一个点。该快速算法的计算量等同于FRFT的计算量，计算结果的精确度取决于连续两次的FRFT运算。