共查询到20条相似文献，搜索用时 176 毫秒
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传统的超宽带穿墙雷达数据采样需要满足 Nyquist 采样定理,超宽带大数据量增大了 A/D 转换时的硬件压力,压缩感知理论突破了传统 Nyquist 采样的限制,它是基于信号的稀疏性,测量矩阵的随机性和非线性优化算法来对信号进行压缩采样和重构.文章针对超宽带穿墙雷达的具体工作过程和穿墙雷达目标成像空间的稀疏性提出了一种基于压缩感知理论的成像方法,并通过仿真表明了该方法的可行性和有效性. 相似文献
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非接触式人体探测雷达利用雷达回波中包含人体的体动和心跳呼吸等生命特征信息,来探测隐藏于固定物后人体目标的存在。本文介绍了一种宽带线性调频连续波体制的非接触式雷达的信号检测方法,基于相谱分析来实现对目标的定位和运动参数提取。 相似文献
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针对基于多姿态角下高分辨一维距离像的雷达目标三维成像,本文提出了一种基于互相关方法的散射中心关联和三维成像算法。该方法在穷举所有由一维距离像提取出的散射中心径向距离之间的任意组合的基础上,对散射中心三维坐标进行量化,通过真假散射中心之间的相关,最终获取目标的三维结构信息。与以往方法相比,该方法算法简单,无需大量的目标测量数据。文中给出了应用该方法进行雷达目标三维成像的步骤,仿真结果证明了该方法的有效性。 相似文献
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本文主要介绍了超宽带穿墙探测雷达;设计了以FPGA和DSP的雷达回波信号处理终端;介绍了该信号处理终端的系统框架、工作原理,并采用双口RAM作为DSP和FPGA之间进行数据传输的缓冲存储器;通过实验,各模块可以相互协调地完成工作,并实现了目标回波信号的采样、算法处理、目标方位显示等功能。 相似文献
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模板支护对混凝土浇筑质量十分重要。本文以某建筑工程墙体支架模板结构为研究对象,在墙体模板设计的基础上,分析了墙模板面板,墙模板内外楞和穿墙螺栓受力,对墙体模板设计结构进行验算,为其他墙体模板设计验算提供了参考依据。 相似文献
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雷达在工作过程中由于特定的工作模式或抗干扰等需求,导致雷达回波在某些距离单元上出现非连续采样时会导致雷达接收信号的频谱存在严重栅瓣问题,从而会影响对目标的检测。因此本文提出了一种基于低秩矩阵填充的方法,利用少量的回波信息对雷达信号进行很大概率的恢复,从而实现非连续采样条件下雷达目标的检测。理论分析和仿真结果表明了该方法的有效性 相似文献
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Ram M. Narayanan 《Journal of The Franklin Institute》2008,345(6):659-678
This paper examines the results of our research on the use of ultrawideband noise waveforms for imaging objects behind walls. The advantages of using thermally generated noise as a probing signal are introduced. The technique of heterodyne correlation used to inject coherence in the random noise probing signal and to collapse the wideband reflected signal into a single frequency are presented. Central to successful imaging through building walls is the characterization of the wideband propagation properties of wall materials and these are discussed. The basic concepts of synthetic aperture radar image formation using noise waveforms and the unique problems associated with the random nature of the transmit waveform are analyzed. We also address issues related to locating, detection, and tracking humans behind walls, using new tools for human activity characterization, namely the Hilbert-Huang Transform approach. The results indicate that noise radar technology combined with modern signal processing approaches is indeed a viable technique for covert high-resolution imaging of obscured stationary and moving targets. 相似文献
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The presence of significant multipath propagation and heavy clutter in indoor environments imposes severe limitations on imaging through walls, rendering through-the-wall radar imaging a difficult and complex proposition. It is highly desirable to properly interpret the radar images and determine the contents of the indoor scene with a high level of confidence. Data collected from multiple vantage points around a structure can be used to improve imaging visibility into the indoor scene, which, in turn, enhances indoor target detection and localization. In this paper, we consider multi-location radar imaging. Image fusion techniques for combining synthetic aperture radar images acquired from multiple locations along two sides of an enclosed structure are presented. Supporting results, based on real-data collected in a semi-controlled laboratory environment, are provided which demonstrate the improved performance of the multiple location scheme compared to operation from a single vantage point. 相似文献
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基于文献统计分析法的专利计量分析研究 总被引：3，自引：0，他引：3
本文在介绍文献统计分析法的基础上,从专利数量统计分析的角度研究了文献统计分析方法在专利计量分析中的适用性和差异性,并从时序变化和国别分布两方面对雷达成像技术的科学论文和专利数量的统计结果进行了对比分析. 相似文献
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This paper addresses the potentials of ultra-wideband (UWB) through-wall imaging radars compared with conventional narrowband systems. The challenges that limit the utilization of high precision UWB systems are examined with the aim of mitigating them. These challenges include multi-path, pulse dispersion, and antenna effects on the pulse shape due to angles of transmission and arrival. The propagation of UWB signals through walls is a crucial factor in determining the success of UWB radar technology. UWB signals, when propagating through walls, not only suffer attenuation but also distortion due to dispersive properties of the walls. This paper examines time- and frequency-domain techniques for measuring the electromagnetic properties of construction materials in the UWB frequency range. The measured parameters provide valuable insights in appreciating the capabilities and limitations of the UWB technology. Special attention is paid to time gating as a mean to extract the direct-path signal from the multi-path components. Both single-pass and multi-pass models are discussed. Multi-pass models account for the multiple reflections within the wall while the single-pass model assumes the possibility of gating out a single transmission. The partition-dependent narrowband propagation model is modified to account for the ultra-wide bandwidth of the signal. The paper illustrates the application of the modified model in indoor environments. The modified model is helpful in estimating the link power budget. It is also useful in studying the performance of UWB systems for indoor communication and positioning applications. 相似文献
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在超宽带穿墙雷达压缩感知成像中,常常使用Rademacher序列作为模拟信息转换器的chipping序列。而这种序列的功率谱类似于高斯白噪声的功率谱,它与回波信号的功率谱不匹配,导致低速采样前信号的信噪比偏低,最终影响了成像效果。文章从低速采样前的平均信噪比最大化入手,构建设计匹配chipping序列的优化算法以导出其成立的条件,给出一种使用马尔科夫链游程长度受限(RLL)序列来设计匹配chipping序列的解决方案。仿真结果表明,使用马尔科夫链RLL序列设计匹配chipping序列的成像结果优于Rademacher序列,其图像的信噪比提高2~3dB。 相似文献
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把通常用于图像处理的CLEAN算法引入到SAR成像处理中,提出一种基于CLEAN 的SAR图像旁瓣抑制方法.分析算法流程,比较点目标仿真结果和RADARSAT-1海洋稀疏目标场景成像结果,表明该方法在保证成像分辨率的同时,能够有效地抑制合成孔径雷达图像的旁瓣. 相似文献
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军用雷达标准化工作是一项重要的基础性工作。为了提高军用雷达标准化水平,在对军用雷达标准化内涵进行分析的基础上对军用雷达标准化原理进行了初步探索,在军用雷达标准化原理的理论指导下将军用雷达标准化过程划分为两个阶段,并基于军用雷达标准化效益的S型曲线对实施标准等的具体工作阶段展开深入研究,提出了军用雷达标准更新时机选择的定量方法。 相似文献
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射频雷达模拟器是逼真度高的一类雷达模拟器,而射频方向图模拟是射频雷达模拟器的重要组成部分。论文提出的天线射频方向图模拟技术可实现多种方向图的仿真,并能用实测天线方向图进行模拟,既满足了雷达模拟器通用性的要求,又满足了雷达模拟器真实性的要求,具有较高的实用价值。 相似文献
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程海平 《科技成果管理与研究》2009,(4):67-70
本文介绍了一种车载雷达的结构总体设计。该雷达采用了转台翻转机构和方舱一体化设计,减少了车辆的改装要求,降低了雷达的制造成本和使用成本。同时还具有多种工作方式,增强了该雷达的阵地适应性。利用液压作为翻转机构的动力来源,结构简单,工作可靠且易维护;同时该雷达还具有良好的人机工程设计和可维性设计。 相似文献