Intrusion Locating Simulation based on Optical Fiber Sensing

The study proposed the simulations of a fiber optical perimeter intrusion detection system. Instead of the optical interferometer, the optical time domain reflectometer (OTDR) is utilized for the intrusion locating. Basically, the quantitative backscattering measurement of the light intensity is the kernel analysis for locating the intrusion position. To analyze the signal of this fiber OTDR perimeter intrusion detection system, theoretical backscattered signal model of delta function approximated scatterers is discussed. A Matlab program is developed to simulate backscattered OTDR light intensity signal via intrusion perturbation and detector noises. The differential method and moving differential method are applied for simulations to estimate the intrusion location. Location errors of the two algorithms under various noise levels are compared and discussed. Simulation results found that the moving differential method under low noise level can effectively locate the intrusion point satisfactory.