Analysis of parameters for a distributed temperature sensing based on Raman scattering

Abstract

This paper presents a theoretical and computational study on the analysis of parameters for distributed temperature sensing in optical fibers, based on spontaneous Raman scattering effect. The parameters studied were the optical power level, the range of frequency modulation and the length of the sensor element, as well as the application of optical frequency domain reflectometry (OFDR). Two different approaches of reading temperature information from the backscattered signal were also tested. First, one considered the pulse response, and later the ratio between the amplitudes of the detected signals were taken. Such analysis has shown the second method is more efficient to detect the peak of hot spot temperature in the fiber. Spatial resolution equal to 0.96 m and a temperature resolution of 0.089°C were achieved using singlemode fiber 30 meters long.