新型高灵敏分布式光纤入侵监测系统  

Highly sensitive distributed optical fiber intrusion monitoring system

作　　者：罗俊[1] 饶云江[1,2] 岳剑锋[1] 冉曾令[1] 

机构地区：[1]电子科技大学宽带光纤传输和通信网技术教育部重点实验室,成都610054 [2]重庆大学光电技术与系统教育部重点实验室,重庆400044

出　　处：《仪器仪表学报》2009年第6期1123-1128,共6页Chinese Journal of Scientific Instrument

基　　金：国家863项目(2007AA01Z245);教育部博士点基金(A0901010120060614017)资助项目

摘　　要：首次提出了一种基于纤维增强塑料(FRP)传感光缆的新型高灵敏相位敏感光时域反射计(Φ-OTDR)分布式光纤入侵监测系统。该方案中传感系统光源采用价格比较便宜且使用比较广泛的窄线宽DFB激光器,并采用光纤饱和体吸收法来压窄激光器的线宽以增强后向瑞丽散射光的干涉效果;在传感光缆部分使用新型的FRP封装的特殊传感光缆,该光缆拥有比普通通信光缆高得多的应力敏感性;并且应用小波分析方法对得到的传感信号进行降噪处理,有效地提高了系统的信噪比。通过以上改进提高了系统对微扰远程定位检测的准确度和灵敏度。实验结果表明该传感系统在2km和6km处均能获得较高信噪比的扰动信号,能有效地预报和定位微扰的发生,由于该系统成本得到有效的控制,可能是目前国际上性价比最好的Φ-OTDR分布式光纤入侵监测系统,可望在入侵监测中获得广泛的应用。A novel Φ-OTDR distributed optical fiber intrusion monitoring system based on fiber reinforced plastic （FRP） encapsulated fiber cable is reported and demonstrated for the first time to our knowledge. A widely used and cheap DFB laser is used as the light source for the sensing system, and an optical fiber saturable absorber is used to narrow the linewidth so as to enhance the interference effect of the Rayleigh backscattering light within the optical fiber. The sensing fiber cable is a special FRP encapsulated fiber cable and it is much more sensitive than the ordinary communication fiber cable. Moreover, wavelet transform method is applied to denoise the sensing signal, which improves the signal to noise ratio （SNR） significantly. Such a system can provide better alarming performance via the improvements mentioned above. In the experiment, the sensing system detects the intrusion signal with a high SNR in locations of 2 km and 6 km. This sensing system is anticipated to be used widely to intrusion monitoring as its cost can be effectively reduced and it may be the best Φ-OTDR distributed optical fiber intrusion monitoring system in terms of performance to price ratio reported so far.

关 键 词：分布式光纤传感器 相位敏感光时域反射计 光纤饱和体吸收法 入侵监测 小波分析 

分 类 号：TP212.14[自动化与计算机技术—检测技术与自动化装置]