{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T15:34:10Z","timestamp":1772206450162,"version":"3.50.1"},"reference-count":53,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2019,6,16]],"date-time":"2019-06-16T00:00:00Z","timestamp":1560643200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100006133","name":"Advanced Research Projects Agency - Energy","doi-asserted-by":"publisher","award":["DE-AR0000540"],"award-info":[{"award-number":["DE-AR0000540"]}],"id":[{"id":"10.13039\/100006133","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We present field deployment results of a portable optical absorption spectrometer for localization and quantification of fugitive methane (CH4) emissions. Our near-infrared sensor targets the 2\u03bd3 R(4) CH4 transition at 6057.1 cm\u22121 (1651 nm) via line-scanned tunable diode-laser absorption spectroscopy (TDLAS), with Allan deviation analysis yielding a normalized 2.0 ppmv\u2219Hz\u22121\/2 sensitivity (4.5 \u00d7 10\u22126 Hz\u22121\/2 noise-equivalent absorption) over 5 cm open-path length. Controlled CH4 leak experiments are performed at the METEC CSU engineering facility, where concurrent deployment of our TDLAS and a customized volatile organic compound (VOC) sensor demonstrates good linear correlation (R2 = 0.74) over high-flow (&gt;60 SCFH) CH4 releases spanning 4.4 h. In conjunction with simultaneous wind velocity measurements, the leak angle-of-arrival (AOA) is ascertained via correlation of CH4 concentration and wind angle, demonstrating the efficacy of single-sensor line-of-sight (LOS) determination of leak sources. Source magnitude estimation based on a Gaussian plume model is demonstrated, with good correspondence (R2 = 0.74) between calculated and measured release rates.<\/jats:p>","DOI":"10.3390\/s19122707","type":"journal-article","created":{"date-parts":[[2019,6,17]],"date-time":"2019-06-17T03:24:41Z","timestamp":1560741881000},"page":"2707","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Field Deployment of a Portable Optical Spectrometer for Methane Fugitive Emissions Monitoring on Oil and Gas Well Pads"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4278-3763","authenticated-orcid":false,"given":"Eric J.","family":"Zhang","sequence":"first","affiliation":[{"name":"IBM Thomas J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chu C.","family":"Teng","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Theodore G.","family":"van Kessel","sequence":"additional","affiliation":[{"name":"IBM Thomas J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9497-1403","authenticated-orcid":false,"given":"Levente","family":"Klein","sequence":"additional","affiliation":[{"name":"IBM Thomas J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ramachandran","family":"Muralidhar","sequence":"additional","affiliation":[{"name":"IBM Thomas J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gerard","family":"Wysocki","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"William M. J.","family":"Green","sequence":"additional","affiliation":[{"name":"IBM Thomas J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,6,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6435","DOI":"10.1073\/pnas.1202407109","article-title":"Greater focus needed on methane leakage from natural gas infrastructure","volume":"109","author":"Alvarez","year":"2012","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1007\/s10584-011-0061-5","article-title":"Methane and the greenhouse-gas footprint of natural gas from shale formations","volume":"106","author":"Howarth","year":"2011","journal-title":"Clim. Chang."},{"key":"ref_3","unstructured":"US Energy Information Administration (2018, March 25). 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