Distributed fiber temperature measurement method and device based on Raman scattering

Abstract

The application discloses a distributed fiber temperature measurement method and device based on Raman scattering. The method comprises when incident light scatters in a sensing fiber, obtaining Raman backward scattered light information, wherein the Raman backward scattered light information includes a light intensity value, the Raman backward scattered light comprises stokes light and anti-stokes light, and the light intensity value of the anti-stokes light changes with temperatures; preprocessing the Raman backward scattered light information, and obtaining the temperature value of each monitoring point on the sensing fiber according to the corresponding relation between the light intensity value of the Raman backward scattered light and the temperatures; and when a temperature is monitored to change abruptly, obtaining the distance between a temperature abrupt change point and the position of emitting the incident light. The mode of the invention can effectively increase a signal to noise ratio, and improve temperature detection precision.

Description

Technical field [0001] This application relates to the field of communication technology, and in particular to a method and device for measuring temperature based on distributed optical fiber based on Raman scattering. Background technique [0002] When the laser pulse is transmitted in the optical fiber, it interacts with the optical fiber molecules, and various forms of scattering occur, such as Rayleigh scattering, Brillouin scattering and Raman scattering. Because Rayleigh scattering is not sensitive to temperature; Brillouin scattering is sensitive to temperature and stress, and is easily interfered by the external environment, which affects the measurement accuracy; Raman scattering is only sensitive to temperature; therefore, the existing distributed optical fiber temperature measurement technology Optical fiber temperature measurement is usually based on the temperature effect mechanism of Raman scattering. Among them, the Raman scattering effect produces Stokes light an...

AI Technical Summary

Problems solved by technology

[0005] Due to the low signal-to-noise ratio of the Raman scattering signal, the existing optical fiber temperature sensor cannot meet the requirements in terms of signal detection accuracy and signal processing capability, and the measured temperature has low accuracy and large error, and cannot accurately locate temperature anomalies. It cannot be widely used in power systems, oil tanks, subsea tunnels and other places that have high requirements for temperature monitoring and where it is difficult to obtain temperature data.

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