提出了一种改进的关于相位敏感光时域反射计(OTDR)系统的信号解调方法。从理论上阐述了该方法的原理,分析了该方法中关键参数(平均次数、滑动窗口和相减间隔)的取值对相位敏感OTDR系统信号处理结果的影响,并且总结了它们取值的指导依据。与常规的数字平均方法对比,利用该方法进行数据处理,有效地解调出扰动信号,进一步说明该方法的可行性:结果表明,该方法根据信号的波动特征将原始数据进行分组,提高了各组数据的相关性,从而明显改善了系统的信噪比,对长距离相位敏感OTDR系统性能的优化有一定的指导意义。
An improved signal demodulated method of phase-sensitive optical time domain reflectometer (OTDR) system was proposed. The principle of the method was illustrated theoretically. The effect of the values of key parameters (average time, moving window, substracting interval) on the result of signal processing of the phase-sensitive OTDR system was analyzed and selection of these key parameters was summarized. Compared with the conventional digital average method, the disturbance signal was effectively demodulated with the method, which illustrated the feasibility of the method further. The result shows that the method increases the correlation of each group data with dividing original data into groups as the fluctuation characteristics of signals, thus improving the SNR of system obviously. This method can extend the performance of long distance phase-sensitive OTDR to some extent.