{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,20]],"date-time":"2026-02-20T19:58:40Z","timestamp":1771617520621,"version":"3.50.1"},"reference-count":65,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2018,6,28]],"date-time":"2018-06-28T00:00:00Z","timestamp":1530144000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000104","name":"National Aeronautics and Space Administration","doi-asserted-by":"publisher","award":["80NSSC17K0110"],"award-info":[{"award-number":["80NSSC17K0110"]}],"id":[{"id":"10.13039\/100000104","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["NRF-2016M1A3A3A02018195"],"award-info":[{"award-number":["NRF-2016M1A3A3A02018195"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Science Foundation of China","doi-asserted-by":"publisher","award":["41671421"],"award-info":[{"award-number":["41671421"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Accurate estimation of terrestrial photosynthesis has broad scientific and societal impacts. Measurements of photosynthesis can be used to assess plant health, quantify crop yield, and determine the largest CO2 flux in the carbon cycle. Long-term and continuous monitoring of vegetation optical properties can provide valuable information about plant physiology. Recent developments of the remote sensing of solar-induced chlorophyll fluorescence (SIF) and vegetation spectroscopy have shown promising results in using this information to quantify plant photosynthetic activities and stresses at the ecosystem scale. However, there are few automated systems that allow for unattended observations over months to years. Here we present FluoSpec 2, an automated system for collecting irradiance and canopy radiance that has been deployed in various ecosystems in the past years. The instrument design, calibration, and tests are recorded in detail. We discuss the future directions of this field spectroscopy system. A network of SIF sensors, FluoNet, is established to measure the diurnal and seasonal variations of SIF in several ecosystems. Automated systems such as FluoSpec 2 can provide unique information on ecosystem functioning and provide important support to the satellite remote sensing of canopy photosynthesis.<\/jats:p>","DOI":"10.3390\/s18072063","type":"journal-article","created":{"date-parts":[[2018,6,28]],"date-time":"2018-06-28T10:53:33Z","timestamp":1530183213000},"page":"2063","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":84,"title":["FluoSpec 2\u2014An Automated Field Spectroscopy System to Monitor Canopy Solar-Induced Fluorescence"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5095-6735","authenticated-orcid":false,"given":"Xi","family":"Yang","sequence":"first","affiliation":[{"name":"Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA"}]},{"given":"Hanyu","family":"Shi","sequence":"additional","affiliation":[{"name":"Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9512-3318","authenticated-orcid":false,"given":"Atticus","family":"Stovall","sequence":"additional","affiliation":[{"name":"Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA"}]},{"given":"Kaiyu","family":"Guan","sequence":"additional","affiliation":[{"name":"Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana and Champaign, Champaign, IL 61801, USA"},{"name":"National Center of Supercomputing Applications, University of Illinois at Urbana and Champaign, Champaign, IL 61801, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5532-932X","authenticated-orcid":false,"given":"Guofang","family":"Miao","sequence":"additional","affiliation":[{"name":"Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana and Champaign, Champaign, IL 61801, USA"}]},{"given":"Yongguang","family":"Zhang","sequence":"additional","affiliation":[{"name":"Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Sciences, Nanjing University, Nanjing 210023, China"},{"name":"Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7468-2409","authenticated-orcid":false,"given":"Yao","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Plant Biology, Center for Spatial Analysis, University of Oklahoma, Norman, OK 73019, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0956-7428","authenticated-orcid":false,"given":"Xiangming","family":"Xiao","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Plant Biology, Center for Spatial Analysis, University of Oklahoma, Norman, OK 73019, USA"}]},{"given":"Youngryel","family":"Ryu","sequence":"additional","affiliation":[{"name":"Department of Landscape Architecture and Rural Systems Engineering, Seoul National University, Seoul 08826, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4775-7943","authenticated-orcid":false,"given":"Jung-Eun","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Earth, Environment, and Planetary Sciences, Brown University, Providence, RI 02912, USA"}]}],"member":"1968","published-online":{"date-parts":[[2018,6,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"834","DOI":"10.1126\/science.1184984","article-title":"Terrestrial gross carbon dioxide uptake: Global distribution and covariation with climate","volume":"329","author":"Beer","year":"2010","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2977","DOI":"10.1002\/2015GL063201","article-title":"Solar-induced chlorophyll fluorescence correlates with canopy photosynthesis on diurnal and seasonal scales in a temperate deciduous forest","volume":"42","author":"Yang","year":"2015","journal-title":"Geophys. 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