The Research On The Technology Of Radar Life-detection

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.