Measurement of temperature and strain simultaneously with high spatial resolution for a long sensing range

This study presents a Brillouin distributed sensor (BDS) with high spatial resolution for the monitoring of temperature and strain simultaneously. Fourier deconvolution (FD), Fourier regularised deconvolution (FRD), and Fourier regularised denoising deconvolution (FRDD) algorithms have been explored to measure the Brillouin backscattered power using the optical time-domain reflectometry technique. The improvement of temperature and strain resolutions along with the spatial resolution using the FRDD algorithm is observed for 50 km sensing range. The numerical simulation process of the proposed sensing system has been simultaneously incorporated to extract temperature and strain information. The simulation results show that the temperature and strain resolutions are observed as 5 degrees K and 138 mu e, respectively, using FRDD compared with the FD algorithm which shows temperature and strain resolutions as 54 degrees K and 1588 mu e, respectively, at a 50-km distance. A high spatial resolution of 9 m is observed of the proposed BDS over the sensing range of 50 km using the FRDD algorithm. In addition, the denoising capability of the proposed FRDD algorithm is validated using the experimentally obtained Rayleigh backscattered signal.