Fig. 4: Experimental results of GO-coded and single-pulse ROTDR.
From: Genetic-optimised aperiodic code for distributed optical fibre sensors

a A 177-bit normalised coding sequence cf(n) measured at the fibre input (blue) and the retrieved df(n) (red). Inset: Zoom-in of normalised cf(n) and df(n) over a time span from 12 to 12.2 μs. b Retrieved temperature profiles over the entire sensing fibre, for single-pulse (blue) and GO-coded (red) schemes. c SNR profiles over the entire sensing fibre, for single-pulse (blue) and GO-coded (red) schemes. d Retrieved temperature profiles around a 5-m-long hotspot located near the fibre far-end. e, f Temperature uncertainty profiles along with the sensing fibre for 2 and 1 m SRs.