Fit attenuation difference temperature self-correction method for distributed optical fiber Raman temperature measurement system

Abstract

The invention relates to a fit attenuation difference temperature self-correction method for a distributed optical fiber Raman temperature measurement system. According to the invention, a Stokes light and anti-Stokes light attenuation coefficient difference equation is obtained by a temperature demodulation principle; a fit curve equation of an attenuation coefficient difference relative to a temperature is obtained by a fit curve; a temperature demodulation equation is obtained by a ratio of the fit curve equation to luminous flux; after demodulation, primary correction on a temperature is implemented; then Rayleigh noise is solved by combining a relationship between Stokes light and anti-Stokes light signals and the Rayleigh noise; further a corrected temperature demodulation formula isobtained; and after demodulation, secondary correction is implemented. The temperature self-correction aim is fulfilled; and compared to a conventional method of eliminating the Rayleigh noise, the fit attenuation difference temperature self-correction method improves temperature correction, implements accurate measurement on the temperature, avoids an error problem caused by approximate equalization processing on Stokes light and anti-Stokes light attenuation coefficients, and meets accurate detection on temperatures of a mine goaf and an adjacent old goaf.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing instruments, in particular to a temperature self-correction method for fitting attenuation difference of a distributed optical fiber Raman temperature measurement system. Background technique [0002] With the sustained and rapid development of the economy, my country's demand for energy is increasing. In order to ensure the safety of coal mine mining and prevent spontaneous combustion, it is necessary to detect the temperature of the coal mine goaf and the adjacent old goaf. At present, the coal mine spontaneous combustion temperature monitoring The distributed optical fiber Raman temperature measurement system adopted, due to the different sensitivity of Stokes light and anti-Stokes light in Raman scattered light to temperature, the optical fiber can be accurately measured by ratio demodulation method combined with optical time domain reflection technology The position and temperatur...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a temperature self-correction method for fitting the attenuation difference of a distributed optical fiber Raman temperature measurement system, which has the advantage of replacing the essential loss and the additional loss with the fitting attenuation difference during temperature demodulation, and solves the problem of The error problem caused by the approximate equal treatment of two attenuation coefficients

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