A perimeter security system based on ultra-weak fiber Bragg grating high-speed wavelength demodulation was proposed. The demodulation system for signal acquisition and high-speed wavelength calculation was designed ba...A perimeter security system based on ultra-weak fiber Bragg grating high-speed wavelength demodulation was proposed. The demodulation system for signal acquisition and high-speed wavelength calculation was designed based on field programmable gate array (FPGA) platform. The principle of ultra-weak fiber Bragg grating high-speed demodulation and signal recognition method were analyzed theoretically, and the Support Vector Machine model was introduced to optimize the event recognition accuracy of the system. A perimeter security experimental system containing 1000 ultra-weak fiber Bragg gratings, ultra-weak fiber Bragg grating sense optical cables with a diameter of 2.0 mm and a reflectivity of 0.01%, steel space frames and demodulation equipments was built to recognize four typical events such as knocking, shaking, wind blowing and rainfall. The experimental resulted show that the system has a spatial resolution of 1m and an acquisition frequency of 200 Hz. The joint time-frequency domain detection method is used to achieve 99.2% alarm accuracy, and 98% recognition accuracy of two intrusion events, which has good anti-interference performance.展开更多
文摘A perimeter security system based on ultra-weak fiber Bragg grating high-speed wavelength demodulation was proposed. The demodulation system for signal acquisition and high-speed wavelength calculation was designed based on field programmable gate array (FPGA) platform. The principle of ultra-weak fiber Bragg grating high-speed demodulation and signal recognition method were analyzed theoretically, and the Support Vector Machine model was introduced to optimize the event recognition accuracy of the system. A perimeter security experimental system containing 1000 ultra-weak fiber Bragg gratings, ultra-weak fiber Bragg grating sense optical cables with a diameter of 2.0 mm and a reflectivity of 0.01%, steel space frames and demodulation equipments was built to recognize four typical events such as knocking, shaking, wind blowing and rainfall. The experimental resulted show that the system has a spatial resolution of 1m and an acquisition frequency of 200 Hz. The joint time-frequency domain detection method is used to achieve 99.2% alarm accuracy, and 98% recognition accuracy of two intrusion events, which has good anti-interference performance.
基金This work was supported in part by the National Science Foundation of China, NSFC （Grant No. 61205070）, and the Key Technology R＆D Program of Hubei Province of China （Grant No. 2014BEC059）.
文摘106 个弱纤维布拉格栅栏(FBG ) 的时间部门 multiplexing 基于一枚戒指反响洞被表明。一个半导体光放大器在洞被连接作为一个放大器以及一个开关工作。106 弱 FBG 与大约 30 dB 的山峰反射率和 5 m 的相等的分离在连续剧沿着 SMF-28 纤维被写。串音并且光谱失真通过理论分析和实验被调查。
基金This work was supported in part by the National Science Foundation of China, NSFC （Gram No. 61205070）, and the Major Program of the National Natural Science Foundation of China, NSFC （Grant No. 61290311）.
文摘一个讯问系统基于二个半导体，为弱纤维布拉格栅栏(FBG ) 的光放大器被建议。第一个半导体光放大器(SOA ) 被用来调制光，并且第二 SOA 通过切换推迟把反映的信号与不同 FBG 分开了。建议系统有更低的插入损失和更高空间的分辨率，和罐头讯问时间部门和波长部门多路的 FBG 数组。与 0.2% 的反射率和沿着光纤维的 5 m 的空间分辨率，多达 50 FBG 被区分表明讯问系统。
