{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:23:19Z","timestamp":1760242999166,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2015,5,5]],"date-time":"2015-05-05T00:00:00Z","timestamp":1430784000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000930","name":"NSF","doi-asserted-by":"publisher","award":["#1029808"],"award-info":[{"award-number":["#1029808"]}],"id":[{"id":"10.13039\/501100000930","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Photosynthetic light-use efficiency (LUE) has gained wide interest as an input to modeling forest gross primary productivity (GPP). The photochemical reflectance index (PRI) has been identified as a principle means to inform LUE-based models, using airborne and satellite-based observations of canopy reflectance. More recently, low-cost electronics have become available with the potential to provide for dense in situ time-series measurements of PRI. A recent design makes use of interference filters to record light transmission within narrow wavebands. Uncertainty remains as to the dynamic range of these sensors and performance under low light conditions, the placement of the reference band, and methodology for reflectance calibration. This paper presents a low-cost sensor design and is tested in a laboratory set-up, as well in the field. The results demonstrate an excellent performance against a calibration standard (R2 = 0.9999) and at low light conditions. Radiance measurements over vegetation demonstrate a reversible reduction in green reflectance that was, however, seen in both the reference and signal wavebands. Time-series field measurements of PRI in a Douglas-fir canopy showed a weak correlation with eddy-covariance-derived LUE and a significant decline in PRI over the season. Effects of light quality, bidirectional scattering effects, and possible sensor artifacts on PRI are discussed.<\/jats:p>","DOI":"10.3390\/s150510616","type":"journal-article","created":{"date-parts":[[2015,5,5]],"date-time":"2015-05-05T10:43:16Z","timestamp":1430822596000},"page":"10616-10630","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Tracking Diurnal Variation in Photosynthetic Down-Regulation Using Low Cost Spectroscopic Instrumentation"],"prefix":"10.3390","volume":"15","author":[{"given":"Martin","family":"Van Leeuwen","sequence":"first","affiliation":[{"name":"Rochester Institute of Technology, Chester F. Carlson Center for Imaging Science,  54 Lomb Memorial Drive, Rochester, NY 14623, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Robert","family":"Kremens","sequence":"additional","affiliation":[{"name":"Rochester Institute of Technology, Chester F. Carlson Center for Imaging Science,  54 Lomb Memorial Drive, Rochester, NY 14623, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jan","family":"Van Aardt","sequence":"additional","affiliation":[{"name":"Rochester Institute of Technology, Chester F. Carlson Center for Imaging Science,  54 Lomb Memorial Drive, Rochester, NY 14623, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,5,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1007\/BF01536732","article-title":"Primary production: The biosphere and man","volume":"1","author":"Whittaker","year":"1973","journal-title":"Hum. Ecol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1016\/j.agee.2004.01.040","article-title":"Carbon cycling in earth systems\u2014A soil science perspective","volume":"104","author":"Janzen","year":"2004","journal-title":"Agric. Ecosyst. Environ."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"815","DOI":"10.1098\/rstb.2007.2185","article-title":"Carbon sequestration","volume":"363","author":"Lal","year":"2008","journal-title":"Philos. Trans. R. Soc. B Biol. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"442","DOI":"10.1126\/science.282.5388.442","article-title":"A large terrestrial carbon sink in North America implied by atmospheric and oceanic carbon dioxide data and models","volume":"282","author":"Fan","year":"1998","journal-title":"Science"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"747","DOI":"10.2307\/2401901","article-title":"Solar radiation and productivity in tropical ecosystems","volume":"9","author":"Monteith","year":"1972","journal-title":"J. Appl. Ecol."},{"key":"ref_6","first-page":"277","article-title":"Climate and the efficiency of crop production in Britain","volume":"281","author":"Monteith","year":"1977","journal-title":"Philos. Trans. R. Soc. B Biol. Sci."},{"key":"ref_7","unstructured":"Heinsch, F.A., Reeves, M., Votava, P., Kang, S., Milesi, C., Glassy, J., Jolly, W.M., Loehman, R., Bowker, C.F., and Kimball, J.S. User\u2019s Guide GPP and NPP (MOD17A2\/A3) Products NASA MODIS Land Algorithm. Available online: http:\/\/www.ntsg.umt.edu\/sites\/ntsg.umt.edu\/files\/modis\/MOD17UsersGuide.pdf."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/j.rse.2013.03.032","article-title":"Effects of irradiance and photosynthetic downregulation on the photochemical reflectance index in Douglas-fir and ponderosa pine","volume":"135","author":"Gamon","year":"2013","journal-title":"Remote Sens. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2415","DOI":"10.1175\/1520-0477(2001)082<2415:FANTTS>2.3.CO;2","article-title":"FLUXNET: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor, and energy flux densities","volume":"82","author":"Baldocchi","year":"2001","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_10","first-page":"35","article-title":"A narrow-waveband spectral index that tracks diurnal changes in photosynthetic efficiency","volume":"41","author":"Gamon","year":"1992","journal-title":"Remote Sens. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1111\/j.1469-8137.2006.01835.x","article-title":"Photoprotection in an ecological context: The remarkable complexity of thermal energy dissipation","volume":"172","author":"Adams","year":"2006","journal-title":"New Phytol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/j.rse.2012.02.008","article-title":"Data assimilation of photosynthetic light-use efficiency using multi-angular satellite data: II Model implementation and validation","volume":"121","author":"Hilker","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1016\/j.rse.2010.08.023","article-title":"The photochemical reflectance index (PRI) and the remote sensing of leaf, canopy and ecosystem radiation use efficiencies","volume":"115","author":"Garbulsky","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/j.agrformet.2010.01.004","article-title":"A simple filtered photodiode instrument for continuous measurement of narrowband NDVI and PRI over vegetated canopies","volume":"150","author":"Garrity","year":"2010","journal-title":"Agric. For. Meteorol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"6277","DOI":"10.5194\/bg-11-6277-2014","article-title":"Retrieval of the photochemical reflectance index for assessing xanthophyll cycle activity: A comparison of near-surface optical sensors","volume":"11","author":"Harris","year":"2014","journal-title":"Biogeosciences"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.agrformet.2011.05.002","article-title":"Biophysical controls of soil CO2 efflux in two coastal Douglas-fir stands at different temporal scales","volume":"153","author":"Jassal","year":"2012","journal-title":"Agric. For. Meteorol."},{"key":"ref_17","unstructured":"Meidinger and Pojar (1991). Ecosystems of British Columbia."},{"key":"ref_18","first-page":"326","article-title":"Intelligent opto sensors\u2019 interfacing based on universal frequency-to-digital converter","volume":"56","author":"Yurish","year":"2005","journal-title":"Sens. Transducers"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"15573","DOI":"10.3390\/s140815573","article-title":"Energy-efficient ZigBee-based wireless sensor network for track bicycle performance monitoring","volume":"14","author":"Garghan","year":"2014","journal-title":"Sensors"},{"key":"ref_20","unstructured":"Faludi, R. (2011). Building Wireless Sensor Networks, O\u2019Reilly Media."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"524","DOI":"10.1007\/BF00410358","article-title":"Photosynthetic responses to light variation in rainforest species","volume":"69","author":"Chazdon","year":"1991","journal-title":"Oecologia"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"G04011","DOI":"10.1029\/2008JG000912","article-title":"Interannual variability of the carbon balance of three different-aged Douglas-fir stands in the Pacific Northwest","volume":"114","author":"Krishnan","year":"2009","journal-title":"J. Geophys. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.agrformet.2003.12.003","article-title":"Sensitivity and uncertainty of the carbon balance of a Pacific Northwest Douglas-fir forest during an El Nino\/La Nina cycle","volume":"123","author":"Morgenstern","year":"2004","journal-title":"Agric. For. Meteorol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/j.agrformet.2004.06.011","article-title":"Inter-annual variability in the leaf area index of a boreal aspen-hazelnut forest in relation to net ecosystem production","volume":"126","author":"Barr","year":"2004","journal-title":"Agric. For. Meteorol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2777","DOI":"10.1016\/j.rse.2008.01.011","article-title":"Separating physiologically and directionally induced changes in PRI using BRDF models","volume":"112","author":"Hilker","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1016\/S0034-4257(01)00224-3","article-title":"Remote sensing of canopy light use efficiency using the photochemical reflectance index. Model and sensitivity analysis","volume":"78","author":"Barton","year":"2001","journal-title":"Remote Sens. Environ."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/j.rse.2014.09.017","article-title":"The need for a common basis for defining light-use efficiency: Implications for productivity estimation","volume":"156","author":"Gitelson","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.rse.2014.04.021","article-title":"Estimation of light-use efficiency through a combinational use of the photochemical reflectance index and vapor pressure deficit in an evergreen tropical rainforest at Pasoh, Peninsular Malaysia","volume":"150","author":"Nakaji","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1038\/nature01213","article-title":"Chloroplast avoidance movement reduces photodamage in plants","volume":"420","author":"Kasahara","year":"2013","journal-title":"Nature"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"D08S11","DOI":"10.1029\/2005JD006017","article-title":"Relationship between gross primary production and chlorophyll content in crops: Implications for the synoptic monitoring of vegetation productivity","volume":"111","author":"Gitelson","year":"2006","journal-title":"J. Geophys. Res."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/5\/10616\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:45:48Z","timestamp":1760215548000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/5\/10616"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,5,5]]},"references-count":30,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2015,5]]}},"alternative-id":["s150510616"],"URL":"https:\/\/doi.org\/10.3390\/s150510616","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2015,5,5]]}}}