Mariñelarena Ollacarizqueta, JonIribas Pardo, HaritzLoayssa Lara, Alayn2018-12-282018-12-2820180146-9592 (Print)1539-4794 (Electronic)10.1364/OL.43.005607https://academica-e.unavarra.es/handle/2454/31909We introduce a simple method to extend the performance of pulse coding techniques in their application to Brillouin optical time-domain analysis sensors (BOTDA). It is based on applying a simple logarithmic processing on the detected probe wave that compensates the deviation from linearity of the sensor response for long code lengths. The technique ensures that the accumulated effect of a sequence of pulses is equal to the linear addition of the effects of the individual components, which is the essential condition to ensure a correct decoding of the probe gain measurement. We experimentally demonstrate the compensation of the Brillouin frequency shift error induced by the accumulated gain nonlinearity. Furthermore, a proof-of-concept 80 km sensing link within a total 200 km fiber loop demonstrated a better than 2 MHz precision with 2 m spatial resolution.application/pdfeng© 2018 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.CodingBrillouin scatteringDistributed optic fiber sensorinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess