Signal Detection And Processing Of Perimeter Intrusion Electromagnetic Sensing System

Perimeter intrusion electromagnetic sensing system is an outdoor perimeter protection system developed in recent years.The system is widely used in airports,military bases,nuclear power plants,industrial plants and other important places,the principle of which is that one leaky coaxial cable is buried shallowly in the ground for signal transmission,and another leaky coaxial cable is buried at the same depth at a certain length for signal reception.The leaky coaxial cable of the protective section forms a stable radar detection field in the space within the alert range.When an intruder enters the protection zone,a disturbance occurs in the detection field,which results in a change in the received signal.By detecting and processing the received signal,it is possible to identify the invasion of the guard area and determine the position of the target,thereby an alarm is given.The content of this article stems from the scientific research project of "Key Technology of Perimeter Intrusion Detection System Based on Leaky Cables".The processing technology of the system received signals is mainly studied.The work and achievements of the thesis are as follows:1.Based on the basic theory,the leaky coaxial cable electromagnetic sensor was modeled and simulated.By analyzing its performance indicators,the main physical and electrical parameters of the leaky coaxial cable electromagnetic sensor were determined.2.Based on the radar target location theory,three kinds of modulated pulse signals of single carrier frequency pulse,linear frequency modulation pulse,and Barker code modulation pulse are studied.These are selected as the system's transmitted signals,and the working principle of the system is analyzed in depth.3.The experimental program is designed and the target intrusion is simulated by the experimenter entering different positions in the system's alert area.Then,the experimental data is collected and processed in the software.The target intrusion position displayed in the processing result is consistent with the experiment.4.The use of field-programmable gate array(Field-Programmable Gate Array,FPGA)is to achieve digital signal detection and processing module,and the redesign of experiments is to evaluate the performance of the module.The experimental results show that the processing module has a positioning accuracy of 1.5 meters and a distance resolution of 10 meters.