LAUSR

A novel distributed temperature variation sensor based on a phase-sensitive optical time-domain Rayleigh reflectometer is described and demonstrated experimentally. The measurement technique employs a standard single-mode fiber probe with dual pulses and allows precise tracking of the backscattered signal optical phase variation in time. The phase variation depends on the fiber temperature, with the experimentally measured calibration factor being consistent with that of the theoretical model. The demonstrated technique is capable of providing an operating range of ~50 km with a spatial resolution of ~15 m and offers a simple alternative to distributed temperature sensors based on Raman and Brillouin scattering.