Patent ID: 8315517
Filing Date: 2012-11-20
Classification: G01M,H04B

Abstract:
1. An optical transmission line monitoring apparatus that takes any of plural pieces of measured information including a light intensity value associated with a distance of an optical transmission line obtained by analyzing a returning light which is measured by launching an optical pulse in a longitudinal direction of an optical fiber constituting the optical transmission line as measured information in normal time, and detects an abnormality of the optical transmission line based on the measured information in normal time and on information measured when an extension/contraction of the optical fiber as a monitoring target is unknown, comprising: a first detection device which detects a first waveform portion which includes at least one waveform peak from a waveform formed from the distance and the light intensity value included in the measured information in normal time; a second detection device which detects a second waveform portion corresponding to the first waveform portion in a waveform in the measured information with regard to the monitoring target, within a previously determined correction range including the peak of the first waveform portion; and an abnormality detection device which detects an abnormality in the waveform in the measured information with regard to the monitoring target independently of the extension/contraction of the optical fiber, based on the first waveform portion detected by the first detection device and the second waveform portion detected by the second detection device.