OPTICAL-FIBER PATH SEARCHING METHOD, OPTICAL-FIBER PATH SEARCHING SYSTEM, SIGNAL PROCESSING DEVICE, AND PROGRAM

摘要

The purpose of the present invention is to provide an optical-fiber path searching method, an optical-fiber path searching system, a signal processing device, and a program that make it possible to extract only a signal generated by an elastic wave propagated through air, thereby excluding the influences of walls, supports, etc. An optical-fiber path searching system according to the present invention utilizes DAS, and is characterized by being provided with: a vibration source 304 that applies an elastic wave to a prescribed region; an optical reflectometry device 305 that is connected to one end of an optical fiber 302 and that measures oscillations of changes in the optical path length from the other end of the optical fiber 302 to each point of the optical fiber 302, caused by the elastic wave applied by the vibration source 304; and a signal processing device 313 that extracts signal components on a high-frequency side higher than a preset cutoff frequency from a signal of the oscillations of changes in the optical path length, measured by the optical reflectometry device 305, and that calculates the distance between the vibration source 304 and each point of the optical fiber 302 by using the signal components.