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The ambiguity function of Chinese standard Digital Television Terrestrial Broadcasting (DTTB) signals for passive radar contains one main peak and many side peaks. The side peaks may cause the false alarms. The relative positions and the reasons for the side peaks are analyzed and a new algorithm for side peaks suppression is proposed in this paper. The algorithm, in consideration of the characteristics of the structure of the frame, can eliminate the side peaks completely in the valid Doppler observation interval by setting the reference signals to zero at equal intervals. Both the simulative and experimental results show that this algorithm can improve the performance of target detection of the passive radar based on DTTB signal. 相似文献
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Passive radar detects moving targets by Cross Ambiguity Function (CAF), which is based on the cross correlation process of the direct-path signal in reference channel and echo signal in receive channel. Thus, the performance of direct-path signal is important to system performance for this type of radar. While the Signal to Noise Ratio (SNR) of direct-path signal is low, it will deteriorate the detection performance. In this paper, how SNR of direct-path signal induces degradation on the SNR of CAF, and how the integration gain affects by integration time are analyzed, both with theoretical analysis and numerical simulation, which are valuable for the R&D of passive radar. 相似文献
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模糊函数是雷达信号理论中极为重要的一个概念,本文对雷达信号中常用的脉冲调幅信号、线性调频信号和巴克码信号的模糊函数进行了计算仿真,并对其进行了分析研究。 相似文献
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通过双基地模糊函数分析比较了数字电视地面广播(DTTB)标准下单载波和多载波2种信号形式分别应用于双基地雷达的性能及目标分辨特性,研究了不同接收角度下,DTTB 系统2种信号应用模式的模糊函数图,得到了双基地模糊函数形式下副峰的相对位置、产生原因以及与单基地模糊函数副峰位置的关系。分析了双基地雷达应用中 DTTB 信号的速度分辨力和距离分辨力,指出 DTTB标准下单载波与多载波信号形式的双基地雷达分辨力大致相同,单载波形式的分辨力相对更优。 相似文献
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太赫兹波是频段介于红外光和毫米波之间的电磁辐射,处于电子学向光学的过渡区域,兼顾了微波穿透特性和红外线成像分辨力高的特点,在雷达、宽带通信、安全探测和遥感侦察等军事领域具有巨大的潜在应用前景。本文介绍了太赫兹成像雷达的技术特点,结合导弹制导的应用要求和技术发展现状,重点分析了太赫兹成像雷达技术应用于制导的可行性,并对相关问题进行了初步探讨。 相似文献
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随着低空空域开放和无人机等航空技术的发展,对城市或郊区等电磁频谱紧张的区域开展低空目标探测愈发重要,采用5G信号作为机会照射源的外辐射源雷达在该领域展现出了广阔的应用前景。相比4G网络,5G波形方案的实现细节发生了本质的改变,因此基于不同外辐射源信号的模糊函数也存在较大差异,而现有文献对基于5G信号的外辐射源雷达模糊函数的相关研究仍然较为缺乏。本文从信号的基本结构入手,采用对比分析的方法,从理论上对5G信号和4G信号在帧结构及物理资源结构等方面存在的差异进行了详细对比;搭建了系统仿真模型,并对基于5G信号的外辐射源雷达的模糊函数进行了仿真实验;最后,针对模糊函数中的各类副峰,分析了该模糊副峰产生的原因以及可能对信号探测性能造成的影响,并对部分副峰的抑制方式进行简单阐述。该文为基于5G信号的外辐射源雷达副峰的抑制提供了新的思路和方向。 相似文献
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Shengqi Zhu Guisheng Liao Haihong Tao Yi Qu Zhengguang ZhouAuthor vitae 《AEUE-International Journal of Electronics and Communications》2011,65(11):906-914
In this paper, we describe an approach for Doppler ambiguity resolution. This approach adopts the fact that unwrapped Doppler centroid is a linear function of range frequency for a given antenna squint angle. On this basis, an alternative azimuth compression method is addressed and performed in range frequency domain to accumulate target energy in the azimuth direction. The resulting trajectories behave as some straight lines with the average slope proportional to absolute Doppler centroid. This slope can be well estimated by image-contrast methods. Theoretical analysis and real measured SAR data show that the proposed approach works well in high- and relatively low-contrast scenes. 相似文献
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对雷达辐射源信号进行模糊函数建模是一种有效的特征提取途径,通过对无意调制的雷达辐射源信号的模糊函数分析,提出了基于模糊函数子空间特征优化的个体识别方法,首先抽取模糊函数的"近零"频偏切片作为辐射源信号的主要特征,继而设计了切片串联策略构建了互补的特征子集对,从而分别利用典型相关分析和鉴别典型相关分析实现了切片特征的融合... 相似文献
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用于多分量线性调频信号的自适应核分布分析 总被引:6,自引:1,他引:5
该文针对多分量线性调频信号,提出了一种新的自适应核时频分布-自适应高斯核分布,并给出了有效的核函数估计准则;以自适应高斯核分布为例,分析了采用自适应核时频分布对信号自身项及交叉项的影响,从而说明自适应核相对于固定核的优势所在;总结了基于模糊域自适应设计多分量线性调频信号核函数的一般方法。计算机仿真结果表明了自适应高斯核分布在抑制交叉项并保持较高时频分辨力方面的有效性。 相似文献
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GongXinbao ZangXiaogang ZhouXilang HuGuangrui 《电子科学学刊(英文版)》2003,20(5):378-382
Based on Immune Programming(IP), a novel Radial Basis Function (RBF) network designing method is proposed. Through extracting the preliminary knowledge about the width of the basis function as the vaccine to form the immune operator, the algorithm reduces the searching space of canonical algorithm and improves the convergence speed. The application of the RBF network trained with the algorithm in the modulation-style recognition of radar signals demonstrates that the network has a fast convergence speed with good performances. 相似文献
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Compressed Sensing (CS) theory is a great breakthrough of the traditional Nyquist sampling theory. It can accomplish compressive sampling and signal recovery based on the sparsity of interested signal, the randomness of measurement matrix and nonlinear optimization method of signal recovery. Firstly, the CS principle is reviewed. Then the ambiguity function of Multiple-Input Multiple- Output (MIMO) radar is deduced. After that, combined with CS theory, the ambiguity function of MIMO radar is analyzed and simulated in detail. At last, the resolutions of coherent and non-coherent MIMO radars on the CS theory are discussed. Simulation results show that the coherent MIMO radar has better resolution performance than the non-coherent. But the coherent ambiguity function has higher side lobes, which caused a deterioration in radar target detection performances. The stochastic embattling method of sparse array based on minimizing the statistical coherence of sensing matrix is proposed. And simulation results show that it could effectively suppress side lobes of the ambiguity function and improve the capability of weak target detection. 相似文献
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针对飞机目标的分类问题,提出了一种双辨别子空间高分辨距离像雷达目标识别方法.该方法首先依据Fisher准则导出距离像总散布矩阵的零空间中不含有辨别信息的结论,利用这一结论,对类间和类内散布矩阵进行预降维,降低了后续计算的复杂度.从全局的角度出发,基于类内散布矩阵零空间与非零空间所包含的辨别信息分别建立辨别子空间,实现对目标的特征提取.对ISAR实测飞机数据进行了分类,并与经典子空间方法进行比较,结果表明所提算法有效改善了目标识别性能. 相似文献
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针对在宽波束高频雷达目标探测中传统傅立叶变换频谱分析方法多普勒分辨率较低的问题,提出了一种全超分辨率的时-空域级联信号处理方法.首先利用多重信号分类(MUSIC)算法获得频域超分辨率谱估计,构造出相应于各信号频率的信号子空间,将原始信号向各子空间进行投影变换以获得相应于各信号频率的阵列快拍,然后利用其进行空域超分辨率谱估计,获得相应的到达角.利用该方法能有效地采用短相干积累时间进行多目标的频率-到达角参数估计,从而有效地提高了宽波束高频雷达的目标探测和跟踪性能.数值仿真实验验证了该方法的有效性. 相似文献
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提出了一种用于雷达目标检测的L型无源双极化标签式雷达目标结构,研究了该标签的雷达散射特性,讨论了标签式雷达目标在机动车交通管制系统中的应用。利用L型金属结构的表面感应电流分布特性提高雷达目标的交叉极化散射特性,将雷达标签置于实际尺寸的机动车模型前窗之上,仿真并比较了机动车贴装雷达标签前后的雷达散射截面。分析表明:这种雷达标签对提高雷达对机动车辆的探测和识别能力实际有效,研究结果对于构建经济实用的机动车交通管制系统具有实际意义。 相似文献
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为提高非线性观测条件下雷达目标的跟踪性能,将序贯处理方法引入均方根容积卡尔曼滤波( SCKF),提出一种带多普勒量测的序贯均方根容积卡尔曼滤波( SSCKF-D)雷达目标跟踪算法,该算法通过建立伪量测去除径向距离和径向速度量测误差方差之间的相关性。基于SCKF算法,按照量测精确度的高低顺序对方位角、俯仰角、径向距离和伪量测序贯处理。 Monte Carlo仿真表明,与SCKF和带多普勒量测的均方根容积卡尔曼滤波( SCKF-D)算法相比,SSCKF-D算法跟踪精度更高,较后者提高20%以上,收敛速度更快,更适用于空间目标跟踪。 相似文献