Research on noise reduction method of long distance optical fiber sensor for transmission line on-line monitoring

Sensor network can significantly improve the perception, management and operation level of energy system. Optical fiber sensors are used for on-line intelligent monitoring of equipment and environment, and send optical signal with OPGW to form a passive optical signal sensor network. In response to features of the long distance transmission line of Energy Internet such as easily be subjected to environmental factors, a noise reduction method based on laser timed frequency hopping was proposed in this paper. Firstly, the application of coherent optical time-domain reflection to long distance optical fiber sensing system was analyzed, and then the method to reduce coherent Rayleigh noise was analyzed. The method of timed frequency hopping of laser frequency controlled by software was proposed and the effectiveness of the described model and method was verified by experiments, the prospects and requirements of next stage are proposed.