基于Φ-OTDR系统事件的快速定位方法

Fast location method based on Φ-OTDR system event

OTDR作为分布式传感器,探测范围越大,所需处理的信号数据量也就越大,这就造成了信号实时处理以及数据存储的困难,另外,在相干探测Φ-OTDR中,由于信号载波的存在,对数据采集卡的采样率也提出了更高的要求,更成倍增加了信号数据量和计算机处理难度。这些因素限制了Φ-OTDR光纤传感系统在工程上的应用范围。文中提出一种基于Φ-OTDR系统事件的快速定位方法,在传统Φ-OTDR相位解调方案基础上增加预处理,使用Φ-OTDR系统采集到的原始数据进行分段,通过相位解调方法确定振动事件所处的区域,在该区域内再次进行解调,确定振动事件的准确位置,从而减轻Φ-OTDR系统对于处理机计算能力的要求,在长距离传感光纤中,用于事件定位的计算成本显著降低,极大地提高了Φ-OTDR系统定位振动事件的实时性。

OTDR is a distributed sensor. The larger the detection range,the larger the amount of signal data that needs to be processed. This causes difficulties in real-time signal processing and data storage. In addition,in coherent detection Φ-OTDR,due to the signal the existence of the carrier wave also puts forward higher requirements on the sampling rate of the data acquisition card,which doubles the amount of signal data and the difficulty of computer processing. These factors limit the application scope of the Φ-OTDR optical fiber sensing system in engineering. A fast event location method based on the Φ-OTDR system is proposed,adding preprocessing on the basis of the traditional Φ-OTDR phase demodulation scheme,using the original data collected by the Φ-OTDR system for segmentation,and determining by the phase demodulation method. The area where the vibration event is located,demodulate again to determine the exact location of the vibration event in this area,thereby reducing the requirement of theΦ-OTDR system for the computing power of the processor. It is used for the calculation of event location in the long-distance sensing fiber. The cost is significantly reduced,which greatly improves the real-time performance of the Φ-OTDR system to locate vibration events.