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雷达波生命探测技术研究

The Research on the Technology of Radar Life-detection

【作者】 赵伟

【导师】 黄春林;

【作者基本信息】 国防科学技术大学 , 电子与通信工程, 2009, 硕士

【摘要】 雷达波生命探测技术主要基于多普勒原理。当雷达波穿透一定障碍物而遇到人体时,反射的回波信号被人体生命活动(如呼吸、心跳等)引起的微动所调制,使得回波信号的一些参数发生改变。我们把回波信号适当处理,就能从中提取出与人体相关的生命特征信息,从而在不接触人体的情况下,探测出在废墟、瓦砾、建筑物下是否有活的生命体存在。利用雷达波探测生命体的方法,克服了传统的探生设备容易受外界环境限制和干扰的缺点,抗干扰能力强,适用于发生塌方、雪崩、地震等灾害后对受伤人员的及时营救,同时也可用于医疗看护及反恐等领域。本文设计的连续波雷达生命探测系统包括雷达天线、现场探测装置和远端测控PDA三部分。现场探测装置包括雷达收发模块和基于DSP的信号处理系统。处理系统以TMS320C5509A为核心,负责对解调后的信号进行实时采集和处理,远端测控PDA部分为搜救人员使用的手持式主机,PDA通过RS232接口从现场探测装置获取数据,同时也能对现场探测装置进行控制。采用基于DSP的雷达生命探测信号处理系统可以基本代替USB数据采集卡和计算机,完成信号的采集、分析和处理。并且具有体积小、重量轻、功耗低、携带方便等优点。本文针对雷达波生命探测系统进行了信号处理的算法研究。生命信号属于低速运动目标信号,它所产生的多普勒频移非常小,微弱的回波信号极易淹没在强杂波背景下。如何更加有效地检测和提取出所需的微弱目标信号即生命特征信号,是研究的重点。本文根据小波变换的多分辨率特性,选择d4小波,在噪声背景下检测和提取生命信号。该方法基于提升算法,完成信号分解、通道提取、信号重构和信号检测等系列处理,比一般滤波方法能更有效地提取和检测出生命信号,实时性、应用性更强。雷达波生命探测仪在武警部队也有广阔的应用前景。

【Abstract】 The technology of radar life-detection is mainly based on the principle of Doppler. When radar wave penetrated some obstacles and encountered the body, signal was modulated by human life activities (such as breathing, heartbeat, etc), some parameters of the signal changed. We can extract life relevant characteristics information from the echo signal after properly dispose. And we can see whether life is existence under ruins, rubble, buildings. The tradional life-detection equipments is always Limitations and interference to external environment, but the method of radar life-detection have a better Anti-interference ability. This method can be able to rescue injured person timely after collapse, avalanche, earthquakes and other disasters, as well as anti-terrorism areas and so on.The life-detection system be design in the article contains three parts, radar antenna, on-site detection device and the PDA for remote monitor and control. The on-site detection devices contains transceiver module and DSP-based pretreatment system, TMS320C5509A is the core of pretreatment system , it take charge of real-time signal sample and processing after demodulation. Remote monitor and control PDA is the handset for the rescue staff. PDA can access data from the on-site detection device though the RS232 interface , and also can control the on-site detection device. Based on DSP this signal processing system can take the place of the computer and USB date sampling card to play the role of signal sampling, analyzing and display. Using this unit to compose the radar-based non-contact life-detection system, not only takes the advantages of small size, light weight., but also easy to carry.The signal processing for the life was discussed in the paper. Life signals are low-velocity target signals with very small Doppler frequency shifts and very weak echo signals easily submerged in clutter noise. It is a keystone to detect and pick up LVT more availably and veraciously in this paper. This article design a method is based on the lifting scheme and considers wavelet cores selection first. Signal decomposition, extraction and reconstruction are all completed on the initial signal repeatedly for several times. These operations require less computation and memory but produce precise results.The radar life-detection also has broad application prospects in the Armed Police Force.

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