Remote Temperature Distribution Sensing Along Optical Fibers

The use of optical fibres as transducers is currently the subject of active research justified by the promise of sensors able to offer high accuracy and measurement bandwidth, small size and immunity from interference even over long transmission paths. However, single point sensors only seldom utilise the very high intrinsic bandwidth of the optical fibre transmission medium. The need has therefore emerged to multiplex a number of sensing elements onto a single fibre or fibre pair and thus to form a sensor network distributed in space. This paper reviews recent progress in a particular class of distributed fibre optic sensors, based on the principle of optical reflectometry, which has considerable similarity to some of the LIDAR measurements reported in the literature.