Signal Processing Technique for Distributed Brillouin Sensing at Centimeter Spatial Resolution

A technique for the accurate processing of experimental data measured with the distributed Brillouin sensor at centimeter spatial resolution is proposed. It uses analytical solutions of the steady-state-coupled intensity equations for stimulated Brillouin scattering. This technique includes experimental parameters such as pulsewidth and extinction ratio, pulse (Stokes) and pump powers, and sensing fiber characteristics. This approach also accounts for the effects induced by the ac and dc parts of the pulse. It is capable of extracting strain components hidden in a distorted single-peak spectrum by the implementation of form factors to analyze the shape of the spectrum. This signal processing technique has been validated by experimental data obtained under controlled laboratory conditions. The good agreement between reconstructed and measured spectra reflects the Brillouin frequency shift and the strain affecting the fiber.