一种减小Φ-OTDR光纤扰动传感系统中频率漂移误差的新定位

A New Localization Algorithm to Reduce The Frequency Drift Error in ΦOTDR Optical Fiber Sensing System

摘要:

针对相位敏感光时域反射计(Φ-OTDR)分布式光纤扰动传感系统中激光器的频率漂移严重影响系统定位准确度的问题,提出了一种新的基于频谱分析的定位算法。该算法将采集的散射曲线数据进行傅里叶变换,然后选择特征频率区间进行功率谱累加得出定位结果,可以有效抑制激光器频漂引起的定位误差。最后搭建了长度为8km的样机进行定位算法的测试,系统的信噪比得到了改善,定位准确性提高,验证了算法的有效性。

Abstract:

The frequency drift of laser greatly affects the positioning accuracy of the phasesensitive optical timedomain reflectometer (ΦOTDR) distributed optical fiber disturbance sensing system. So a new localization algorithm based on spectrum analysis was proposed to replace the traditional timedomain moving difference and average algorithm. The collected scattering curve data was taken as the Fourier transform, and then the characteristic frequency interval was selected to calculate the location result, which can effectively suppress the positioning error caused by the laser frequency drift. In addition, a prototype of 8km was built to test the positioning algorithm. Test results indicate that the signaltonoise ratio of the final system is improved, and the effectiveness of the algorithm is verified.