| 摘要 |
Optical time-domain reflectometry can be used to sense respective values of a physical parameter, such as temperature, at different locations along an optical fibre (2). Prior broad spectrum methods call for special correction techniques to account for differential attenuation. Improvements in accuracy can be obtained in relation to prior art methods, without the use of significantly more complicated signal processing circuitry, by ensuring that back-scattered optical radiation used to produce output signals indicative of the values being sensed is restricted to a preselected single spectral line resulting from inelastic scattering in the fibre, for example one of the Anti-Stokes Raman lines, or to two mutually adjacent such lines. |
