Accuracy improvement of Raman distributed temperature sensors based on eliminating Rayleigh noise impact

A novel algorithm of measuring the Rayleigh noise for the optic fiber Raman distributed temperature sensor (RDTS) systems is proposed. This new algorithm is available to solve the temperature measurement inaccuracy caused by the Rayleigh noise. The impact of Rayleigh noise on the temperature measurement accuracy is revealed theoretically for the first time. Based on this novel algorithm, experiments are performed to figure out the Rayleigh noise and validate its impact on temperature measurement accuracy. The experiment results indicate that the Rayleigh noise occupies about 15% of the signal light (anti-Stokes), which is in accord with the computation result based on the device parameters, and the temperature measurement error could be reduced from about 7% to less than 2% by eliminating the Rayleigh noise. (C) 2013 Elsevier B.V. All rights reserved.