摘要
在基于布里渊散射的光时域反射计(BOTDR)中,信噪比和空间分辨率相互制约,而脉冲编码技术是将探测脉冲编码后注入传感光纤,从而在保证空间分辨率的同时提高入射信号的功率,提高系统信噪比。分析了Golay、Simplex和CCPONS码应用于BOTDR系统的编解码过程及编码增益,研究了基于脉冲编码的本地外差BOTDR分布式传感系统原理和组成,并利用MATLAB对采用三种编码技术的系统性能进行了仿真。仿真结果表明,采用脉冲编码技术后,系统的温度和应变分辨率得到有效地提高,并且编码长度越长,系统性能提升效果越明显,CCPONS码比另外两种码型更具有优越性。
The restriction relationship of signal-to-noise ratio （SNR） and spatial resolution have not been resolved in Brillouin optical time domain refleetometer （BOTDR）, and pulse coding technology can effectively improve the SNR under the premise of maintaining the spatial resolution, then improve the resolution of temperature and strain of the system consequently. The principle of pulse coding BOTDR system based on heterodyne detection is analyzed. On the basis of encoding and decoding principle and coding gain of Golay code,Simplex code and CCPONS code, the principle and composition of the distributed sensing system of pulse code BOTDR has been studied and the performance of the system using different pulse code modulation are analyzed and compared by MATLAB. The results show that the pulse coding technology can effectively improve the temperature and strain resolution of BOTDR system, the system can achieve the better performance with the increase of the code length, moreover, CCPONS code modulation is superior to the other two codes.
出处
《激光杂志》
北大核心
2017年第1期75-79,共5页
Laser Journal
基金
国家自然科学基金(61377088)
河北省自然科学基金(F2014502098
F2015502059)
中央高校基本科研业务费专项资金(2014XS77)
关键词
布里渊散射
外差检测
脉冲编码
温度、应变分辨率
brillouin scattering
heterodyne detection
pulse coding
temperature and strain resolution
