【作者】 李鹏飞；

【导师】 朱国富；

【作者基本信息】 国防科学技术大学 ， 信息与通信工程， 2011， 硕士

【摘要】 超宽带穿墙雷达作为一种新兴的研究领域,已经引起越来越多的关注。因为其可以穿透墙壁等介质,对墙后的目标进行探测,在军用和民用领域都可以得到广泛的应用。本文通过超宽带穿墙雷达人体动目标检测技术的研究,对穿墙探测中若干问题进行了深入的分析。本文首先简要介绍了国内外超宽带穿墙雷达研究现状,具体介绍了两种现有的超宽带穿墙雷达系统。提出了穿墙探测存在的主要问题,并阐述了本文的主要工作。针对超宽带天线导致信号的色散,分析了超宽带天线色散的具体成因。天线色散将导致回波信号的展宽,能量的分散,对目标检测极为不利。针对色散补偿数据,本文采用了一种新的检验方法,可以准确的判断色散补偿数据的有效性。针对穿墙探测中杂波干扰,分析了背景杂波的主要组成。针对背景杂波相对静止的特性,建立了高斯概率分布模型。研究不同典型杂波抑制算法优缺点及相互联系,并指出目标运动状态对杂波抑制效果的影响,确定了不同杂波抑制算法的使用环境。针对目标检测,本文提出了一种递归的门限更新公式,使门限的计算和背景相消的结果相联系,大大减少了门限计算的运算量,并使门限计算具有实时性。针对穿墙探测中出现的RFI干扰,分析指出对于穿墙探测等近距离探测,RFI干扰主要表现为第二类未知时变RFI干扰。通过RFI干扰对回波影响的研究,指出其在时域和频域的表现形式。分析了一般算法的优点与不足。针对RFI的时频特性,提出了一种自适应选择RFI抑制算法,并用实验数据对其进行验证。更多还原

【Abstract】 As an emerging field of study, UWB TWR has attracted more and more attention. Because it could penetrate wall or other media to detect target behind the wall, UWB TWR could be widely used both in military and civilian areas. This paper deep analyzes several problems in detecting through the wall via the study of moving target detection of human on UWB TWR.First, this paper introduces the situation of study of UWB TWR at home and abroad. Two existing UWB TWR systems are concretely introduced. Then the main problems in detecting through the wall are proposed, and the main work of this paper is specified.As for signal dispersion result form UWB antenna, this paper analyses concrete cause of UWB antenna dispersion. Antenna dispersion causes the echoes broadening, energy dispersion, extremely detrimental to target detection. As for dispersion compensation data, we use a new test method that could accurately determine the validityAs for clutter interference in detecting through the wall, this paper analyses main components of the background clutter. For the relatively static characteristics of the background clutter, we establish the Gaussian probability distribution model. Then we study the advantages and disadvantages of different typical clutter suppression algorithm, and indicate the relationship between the target motion states with the performance of clutter suppression to determine the use environment of different clutter suppression algorithm. As for target detection, this paper proposes a recursive formula for the threshold update. The new formula combines threshold calculation with background subtraction, greatly reducing the computation of threshold calculation, and make a real-time threshold calculation.As for RFI in detecting through the wall, this paper analyses and indicates that for detecting through the wall or other close range detecting RFI mainly represent as the second class of unknown time-variable RFI. Through the study the effect of RFI to echoes, we indicate its representation in the time domain and frequency domain. We analyses the advantage and disadvantage of the general algorithm. For time-frequency characteristic of RFI, a new RFI suppression algorithm with adaptive selection is proposed, and its validity is certified by experimental data.更多还原