Evaluating the performance of a double integrating sphere in measurement of reflectance, transmittance, and albedo of coniferous needles

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.authorHovi, Aarneen_US
dc.contributor.authorMõttus, Mattien_US
dc.contributor.authorJuola, Jussien_US
dc.contributor.authorManoocheri, Farshiden_US
dc.contributor.authorIkonen, Erkkien_US
dc.contributor.authorRautiainen, Miinaen_US
dc.contributor.departmentDepartment of Built Environmenten
dc.contributor.departmentDept Signal Process and Acousten
dc.contributor.groupauthorGeoinformaticsen
dc.contributor.groupauthorMetrology Research Instituteen
dc.contributor.organizationVTT Technical Research Centre of Finlanden_US
dc.date.accessioned2020-04-03T09:48:17Z
dc.date.available2020-04-03T09:48:17Z
dc.date.issued2020-01-01en_US
dc.description| openaire: EC/H2020/771049/EU//FREEDLES
dc.description.abstractLeaf reflectance and transmittance spectra are essential information in many applications such as developing remote sensing methods, computing shortwave energy balance (albedo) of forest canopies, and monitoring health or stress of trees. Measurement of coniferous needle spectra has usually been carried out with single integrating spheres, which has involved a lot of tedious manual work. A small double integrating sphere would make the measurements considerably faster, because of its ease of operation and small sample sizes required. Here we applied a compact double integrating sphere setup, used previously for measurement of broad leaves, for measurement of coniferous needles. Test measurements with the double integrating sphere showed relative underestimation of needle albedo by 5–39% compared to a well-established single integrating sphere setup. A small part of the bias can be explained by the bias of the single sphere. Yet the observed bias is quite significant if absolute accuracy of measurements is required. For relative measurements, e.g. for monitoring development of needle spectra over time, the double sphere system provides notable improvement. Furthermore, it might be possible to reduce the bias by building an optimized measurement setup that minimizes absorption losses in the sample port. Our study indicates that double spheres, after some technical improvement, may provide a new and fast way to collect extensive spectral libraries of tree species.en
dc.description.versionPeer revieweden
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationHovi, A, Mõttus, M, Juola, J, Manoocheri, F, Ikonen, E & Rautiainen, M 2020, ' Evaluating the performance of a double integrating sphere in measurement of reflectance, transmittance, and albedo of coniferous needles ', Silva Fennica, vol. 54, no. 2, 10270 . https://doi.org/10.14214/sf.10270en
dc.identifier.doi10.14214/sf.10270en_US
dc.identifier.issn0037-5330
dc.identifier.otherPURE UUID: 46ff19c1-7e88-43bb-9b1d-e818c5636edfen_US
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/46ff19c1-7e88-43bb-9b1d-e818c5636edfen_US
dc.identifier.otherPURE LINK: http://www.scopus.com/inward/record.url?scp=85081022099&partnerID=8YFLogxKen_US
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/41557422/article10270.pdfen_US
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/43647
dc.identifier.urnURN:NBN:fi:aalto-202004032677
dc.language.isoenen
dc.publisherFINNISH SOC FOREST SCIENCE-NATURAL RESOURCES INST FINLAND
dc.relationinfo:eu-repo/grantAgreement/EC/H2020/771049/EU//FREEDLESen_US
dc.relation.ispartofseriesSilva Fennicaen
dc.relation.ispartofseriesVolume 54, issue 2en
dc.rightsopenAccessen
dc.subject.keywordAlbedoen_US
dc.subject.keywordNeedle carrieren_US
dc.subject.keywordReflectanceen_US
dc.subject.keywordSpectraen_US
dc.subject.keywordTransmittanceen_US
dc.subject.keywordVegetationen_US
dc.titleEvaluating the performance of a double integrating sphere in measurement of reflectance, transmittance, and albedo of coniferous needlesen
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi
dc.type.versionpublishedVersion
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