A temperature self-correction method for fitting attenuation difference in a distributed optical fiber Raman temperature measurement system

Abstract

The invention relates to a temperature self-correction method for fitting the attenuation difference of a distributed optical fiber Raman temperature measurement system. The invention obtains the Stokes light and anti-Stokes light attenuation coefficient difference equation through the temperature demodulation principle. Fit the curve to obtain the fitting curve equation of the attenuation coefficient difference with respect to the temperature, and obtain the temperature demodulation equation through the ratio of the fitting curve equation and the luminous flux, and realize the preliminary correction of the temperature after demodulation, and then combine the Stokes light and the inverse The relationship between the Tox optical signal and Rayleigh noise is solved, and the modified temperature demodulation formula is further obtained. After demodulation, it is corrected again to achieve the purpose of temperature self-correction, which is comparable to the traditional method of eliminating Rayleigh noise. The temperature correction amount is relatively increased, the accurate measurement of temperature is realized, and the error problem caused by the approximate equalization of Stokes light and anti-Stokes light attenuation coefficients is avoided. Accurate detection of empty space temperature.

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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