A Distributed Optical Fiber Sensing System for Suppressing Common Mode Noise and Its Suppressing Method

Abstract

The invention discloses a distributed optical fiber sensing system for restraining common-mode noise and a restraining method thereof. One optical fiber section in the distributed optical fiber sensing system is selected for noise insulation and vibration insulation treatment to serve as a reference optical fiber, a signal for the reference optical fiber section is obtained and not interfered by external environment and only contains a common-mode noise signal, then the signal for the reference optical fiber is removed from signals of other positions in the distributed optical fiber sensing system, and therefore the common-mode noise in the distributed optical fiber sensing system is eliminated; the reference optical fiber can be freely selected, and is suitable for distributed optical fiber sensing systems such as an optical fiber hydrophone array system, an acceleration sensor array system or a sensing optical fiber; on the basis that no structures are additionally arranged, the common-mode noise signal in the distributed optical fiber sensing system is effectively restrained.

Description

technical field [0001] The invention relates to optical fiber sensing technology, in particular to a distributed optical fiber sensing system for suppressing common mode noise and a suppression method thereof. Background technique [0002] Distributed optical fiber sensing is a new type of sensing technology, and the sensing distance can range from hundreds of meters to hundreds of kilometers. Distributed optical fiber sensing has been widely used in oil pipeline monitoring, perimeter security and other fields due to its advantages of anti-electromagnetic interference, high sensitivity and long sensing distance. [0003] A widely used type of distributed optical fiber sensing is distributed acoustic sensing (DAS), which is generally based on the principle of interference or backscattering. Fiber-optic hydrophones and fiber-optic acceleration sensors are commonly used based on the principle of interference, and phase-sensitive optical time-domain reflectometers (Φ-OTDR) are ...

AI Technical Summary

Problems solved by technology

The existing technology mainly has the following three defects: (1) it is necessary to make an additional reference probe, which increases the overhead of the system; (2) the reference probe needs complete insensitivity to sound pressure and acceleration, which is quite difficult to implement; (3) The system needs to be properly designed to place this reference probe, adding to the complexity of the system

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