Wideband Noise Radar For Intrusion Detection

Intrusion detection technologies are widely used in area protection to protect people and public property.The existing intrusion detection technologies include lidar,optical/thermal infrared camera,electronic fence,vibration cable sensor,optical fiber sensor,and intrusion detection radar.In addition to the intrusion detection radar,other intrusion detection technologies generally have the defects such as poor concealment and being easily affected by ambient temperature,visibility,and noisy vibration.The intrusion detection radar uses leaky cables or conventional antennas to transmit probe signals and receive echo signals,thus constructing an invisible electromagnetic protection area,which makes up for the above shortcomings.However,limited by the inherent characteristics of the probe signals,the intrusion detection radar still has some problems such as low localization accuracy and range resolution,weak anti-electromagnetic interference(anti-EMI)ability,and difficult to realize the whole-process monitoring of multiple intrusion.Therefore,it is of great significance engineering application value to carry out the research of intrusion detection radar.As a natural random signal,noise signal not only has the wide and flat spectrum and the good autocorrelation characteristics,but also has a simple structure which is easy to implement.As the radar probe signal,the noise signal can not only obtain the localization accuracy and range resolution of centimeter scale,but also realize the anti-EMI detection.Therefore,the wideband noise signal is used as the probe signal of intrusion detection radar in this paper.Then,the guided radar based on leaky cables and the single-transmitter-multiply-receivers radar based on conventional antennas are proposed respectively.Finally,a hybrid wideband noise radar for intrusion detection is proposed by combining the above two radars,so as to realize the intrusion warning at the protected area perimeter and the intrusion localization and tracking within the protected area.The main research work is summarized as follows:(1)The advantages and disadvantages of the existing intrusion detection technologies and their working principles were summarized.In addition,the research status of the intrusion detection guided radar based on leaky cables and the intrusion monitoring radar based on conventional antennas were emphatic introduced.In this paper,the wideband noise signal was introduced into the intrusion detection radar.(2)A leaky cable guided radar using the wideband noise signal was proposed and experimentally demonstrated.This radar uses the wideband noise signal as the probe signal and a pair of parallel leaky cables with a certain interval to realize the transmission and reception of the noise signal.By comparing the correlation traces before and after intrusion,the intrusion distance of intruders along the leaky cables is detected according to the correlation peak position.The experimental results show that the guided radar can simultaneously detect the intrusion range of multiple intruders,and distinguish human targets and small animals according to the correlation peak height.The range resolution and dynamic range are 30 cm and 30 d B,respectively,and the maximum detection range is estimated to be185 m.In addition,the anti-EMI ability of guided radar are verified by experiments.Even if there exist different interference signals in the detection environment,this radar can still realize the accurate intrusion detection.(3)A single-transmitter-multiply-receivers radar utilizing the wideband noise signal was proposed and experimentally demonstrated.This radar transmits and receives the wideband noise signal by one transmitting antenna and multiply receiving antennas.Based on the correlation ranging and two-dimensional ellipse localization method,the intruder can be located and tracked.The experimental results show that this radar can locate and track multiple intruders.The localization error is within 10 cm,and the range resolution can reach19 cm.Meanwhile,this radar can also realize the anti-EMI detection.(4)A hybrid wideband noise radar for intrusion detection was proposed and experimentally demonstrated.This radar uses the wideband noise signal as the probe signal,and combines two radar systems including the guided radar based on leaky cables and the single-transmitter-multiply-receivers radar.On the one hand,the guided radar based on leaky cables is used to realize the intrusion warning at the protected area perimeter.On the other hand,the intrusion localization and tracking within the protected area is realized by the single-transmitter-multiply-receivers radar.The experimental results show that the proposed hybrid radar can not only realize the early warning,localization and tracking of multiple intruders,but also has the strong anti-EMI ability.In intrusion warning,the range resolution of guided radar based on leaky cable is 30 cm,and the range resolution of the single-transmitter-multiply-receivers radar is 19 cm in the intrusion location/tracking.