The Positioning of Vibration Source using Telecom Fiber Optic Networks

We propose a simple method for position of vibration source in distributed optical acoustic sensing (DAS) technology. Different from the traditional method of using DAS to locate the vibration source, it can only indicate the corresponding position on the sensing fiber. This method uses sensing optical fibers in two independent telecom cables to measure the distance of vibration source along each corresponding cable and combine the ratio of vibration power received from two sensing fibers to calculate the geographical coordinate of the vibration sources. Therefore, it provides not only the distributed acoustic information along the entire fiber link, but also thus external acoustic signals from an arbitrary point can be detected and located. In this paper, two kinds of deployed telecommunication optical cable route cases are illustrated the geographic coordinates of the vibration source obtained by this method. Through this method it improved the accuracy of positioning vibration source and enhanced the feasibility and diversity of DAS applications.