Abstract:
Over the past five years, Distributed Temperature Sensing (DTS) along fiber
optic cables using Raman backscattering has become an important tool in the
environmental sciences. Many environmental applications of DTS demand very accurate
temperature measurements, with typical RMSE < 0.1 K. The aim of this paper is to
describe and clarify the advantages and disadvantages of double-ended calibration to
achieve such accuracy under field conditions. By measuring backscatter from both ends of
the fiber optic cable, one can redress the effects of differential attenuation, as caused by
bends, splices, and connectors. The methodological principles behind the double-ended
calibration are presented, together with a set of practical considerations for field
deployment. The results from a field experiment are presented, which show that with
double-ended calibration good accuracies can be attained in the field.
