论文部分内容阅读
基于多波干涉原理,建立了调制器消光比(ER)不理想条件下基于相位敏感光时域反射(OTDR)的光纤分布式扰动传感器(FDDS)光路系统输出信号模型,研究了调制器ER对FDDS定位精度的影响机理。仿真结果表明:调制器的ER不理想引起泄漏光产生的后向散射相干曲线是噪声源,它会导致传感器的信噪比(SNR)恶化。因此,调制器的ER是引起定位误差甚至传感器无法定位的一个关键因素;当调制器的ER分别低于10.2dB和7.8dB时,依据有扰动减无扰动定位方法以及移动平均和移动差分算法得到的传感器SNR低于2dB,定位算法失效。通过调节声光调制器的驱动电压来改变衍射效率从而改变调制器的ER,实验结果与数值仿真基本一致。
Based on the principle of multi-wave interference, an output signal model of optical fiber distributed disturbance sensor (FDDS) optical system based on Phase Sensitive Optical Time-Domain Reflectance (OTDR) under the condition of modulator extinction ratio (ER) Influence Mechanism of FDDS Positioning Accuracy. The simulation results show that the backscatter coherence curve caused by the leakage of light is not ideal because of the erroneous ER of the modulator, which causes the signal to noise ratio (SNR) of the sensor to deteriorate. Therefore, the ER of the modulator is a key factor that causes the positioning error and even the sensor can not be located. When the ER of the modulator is less than 10.2dB and 7.8dB respectively, the perturbed and non-perturbed localization method and the moving average and moving difference algorithm The sensor SNR is lower than 2dB, the positioning algorithm fails. By adjusting the driving voltage of the acousto-optic modulator to change the diffraction efficiency and thus the ER of the modulator, the experimental results are basically consistent with the numerical simulation.