High spatial resolution temperature sensing based on intensity calculation in RDTS system

Conventional Raman Distributed Temperature Sensing (RDTS) systems continuously measure multiple regions with a length less than the minimum fiber length required for accurate temperature measurement, the demodulated temperature will have a large error with the true temperature. To obtain high spatial resolution temperature measurements at each region on the sensing fiber, a novel temperature demodulation scheme is proposed in this paper. Firstly, the length of the sensing fiber is divided into multiple regions at equal intervals according to the sampling spacing of data acquisition card, then the relation between temperature and Raman intensity is obtained for each sampling point of temperature rise curve generated by a single region, and the temperature information of each region can be obtained by solving the joint equation finally. The experimental results show that this scheme can improve the spatial resolution of the conventional RDTS system from 4 m to 0.5 m, and the temperature demodulation of five regions with a length of 0.5 m can be realized with a temperature accuracy of ±2.3°C.