Fig. 5: Strain sensing using the QIR-DFC technique over a 1 km fibre.
From: Time-expanded phase-sensitive optical time-domain reflectometry
a Dynamic stress map around the perturbed area. b Stress profile experimentally obtained at a particular instant of time. As in the case of the results obtained for temperature sensing, the observed distribution is the result of convolving the applied stress distribution by a rectangular resolution window, leading to a roughly triangular-shaped profile. c Amplitude of the Fourier transform of a vertical profile in a located at 952.53 m
