【作者】 牟妙辉；

【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， 2009， 硕士

【摘要】 在反恐和人质救援行动中,执法人员通常需要对目标隐藏的建筑物进行非接触式的探测,以实现对隐藏目标的定位和跟踪,从而提高作战人员对周围环境的态势感知能力。本文研究的超宽带穿墙生命探测雷达(UWB-TWLDR)就是实现这些功能的新型探测装备。本文从UWB-TWLDR的功能需求及系统复杂度出发,选择冲激脉冲波形作为发射信号形式,在分析电磁波穿墙性能的基础上,讨论了面向雷达应用的系统参数选择。考虑到系统工作的隐蔽性及复杂的城区电磁环境,研究了一种超宽带时域调制冲激脉冲信号波形,重点分析了时间调制码参数对其功率谱密度的影响,进一步研究了其潜在的抗RFI性能。在分析穿墙雷达回波信号的基础上,建立了穿墙雷达的工作模型,根据人体目标运动的特点,利用积累平均背景相消对小运动的人体目标进行杂波抑制,对于大运动的目标则利用脉冲对消的杂波抑制方法。针对距离历史图像域RFI的特点,提出了一种幅度均衡的干扰抑制方法。在分析静止目标多普勒谱和干扰、杂波谱在慢时间域不同特点的基础上,提出了一种慢时间滤波的杂波和随机RFI抑制方法。根据TWLDR原理样机的系统要求,以Visual C++ 6.0为平台,设计了系统的软件界面,实现了数据采集功能,并利用VC与MATLAB的混合编程技术,实现了准实时的数据处理功能。最后,以水泥砖墙为障碍物,利用原理样机系统做了大量实验,对上述的思想和算法进行了验证。更多还原

【Abstract】 In antiterrorism and hostage situations, law enforcement officers usually need to inspect the building non-contact where the targets hide in order to locate and track the concealed targets, which could enhance officers’the ability of situational awareness. The Through-the-Wall Life-Detecting Radar(TWLDR) is a new candidate equipment which can finish these tasks.In terms of function requirement and complexity of the TWLDR system, this thesis selects the impulse waveform as the transmitting signal. The penetrating performance of electromagnetic wave is analyzed, and then choice of system parameters is discussed based on its application. In view of working covertness and complex electromagnetic circumstances, the time-modulated ultra-wideband impulse signal is studied. Then the influence of the modulating parameters to its power spectrum density is analyzed and the discussion of anti-RFI capability of the signal is followed.The working model of TWLDR is established based on the analysis of targets echo. In terms of moving trait of human being, the integration averaging background subtraction is used for clutter suppression for person with small motion, while for person with big motion, the pulse cancellation is applied. With a view to the RFI characteristic in the range-time history image, the amplitude equilibrium method is developed for interference suppression. The difference of doppler spectrum of static person and that of clutter and interference in the slow-time frequency response is emphasized, based on which a slow-time filtering technique is developed to suppress clutter and random RFI.According to the requirements of TWLDR model machine, the system software interface is designed based on Visual C++ 6.0. The data collection is achieved as well as quasi-real-time data processing utilizing mix-programming technique of VC and MATLAB.Finally, the performances of the algorithms cited above are validated by the experiments for penetrating cement brick wall with the model machine.更多还原