{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T02:23:58Z","timestamp":1777602238668,"version":"3.51.4"},"reference-count":48,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,3,6]],"date-time":"2022-03-06T00:00:00Z","timestamp":1646524800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000288","name":"Royal Society","doi-asserted-by":"publisher","award":["CHL\/R1\/180350"],"award-info":[{"award-number":["CHL\/R1\/180350"]}],"id":[{"id":"10.13039\/501100000288","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000270","name":"Natural Environment Research Council","doi-asserted-by":"publisher","award":["NE\/S012877\/1, NE\/T005890\/1"],"award-info":[{"award-number":["NE\/S012877\/1, NE\/T005890\/1"]}],"id":[{"id":"10.13039\/501100000270","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A Brillouin distributed acoustic sensor (DAS) based on optical time-domain refractometry exhibiting a maximum detectible strain of 8.7 m\u03b5 and a low signal fading is developed. Strain waves with frequencies of up to 120 Hz are measured with an accuracy of 12 \u03bc\u03b5 at a sampling rate of 1.2 kHz and a spatial resolution of 4 m over a sensing range of 8.5 km. The sensing range is further extended by using a modified inline Raman amplifier configuration. Using 80 ns Raman pump pulses, the signal-to-noise ratio is improved by 3.5 dB, while the accuracy of the measurement is enhanced by a factor of 2.5 to 62 \u03bc\u03b5 at the far-end of a 20 km fiber.<\/jats:p>","DOI":"10.3390\/s22052047","type":"journal-article","created":{"date-parts":[[2022,3,6]],"date-time":"2022-03-06T20:40:02Z","timestamp":1646599202000},"page":"2047","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Long Range Raman-Amplified Distributed Acoustic Sensor Based on Spontaneous Brillouin Scattering for Large Strain Sensing"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4766-6654","authenticated-orcid":false,"given":"Shahab","family":"Bakhtiari Gorajoobi","sequence":"first","affiliation":[{"name":"Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0001-6080","authenticated-orcid":false,"given":"Ali","family":"Masoudi","sequence":"additional","affiliation":[{"name":"Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5730-0499","authenticated-orcid":false,"given":"Gilberto","family":"Brambilla","sequence":"additional","affiliation":[{"name":"Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5163","DOI":"10.1109\/JLT.2021.3078747","article-title":"Phi-OTDR Based On-Line Monitoring of Overhead Power Transmission Line","volume":"39","author":"Ding","year":"2021","journal-title":"J. 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