Comparison of Reflectance Measurements Acquired with a Contact Probe and an Integration Sphere: Implications for the Spectral Properties of Vegetation at a Leaf Level

0464496 - ÚVGZ 2017 RIV CH eng J - Journal Article
Potúčková, M. - Červená, L. - Kupková, L. - Lhotáková, Z. - Lukeš, Petr - Hanuš, Jan - Novotný, Jan - Albrechtová, J.
Comparison of Reflectance Measurements Acquired with a Contact Probe and an Integration Sphere: Implications for the Spectral Properties of Vegetation at a Leaf Level.
Sensors. Roč. 16, č. 11 (2016), č. článku 1801. E-ISSN 1424-8220
R&D Projects: GA MŠMT(CZ) LO1415
Research Infrastructure: CzeCOS II - 90061
Institutional support: RVO:67179843
Keywords : broadleaved leaf * broadleaved plants * conifers * contact probe * integration sphere * needle * spectroradiometer * spectroscopy
Subject RIV: EH - Ecology, Behaviour
Impact factor: 2.677, year: 2016

Laboratory spectroscopy in visible and infrared regions is an important tool for studies dealing with plant ecophysiology and early recognition of plant stress due to changing environmental conditions. Leaf optical properties are typically acquired with a spectroradiometer coupled with an integration sphere (IS) in a laboratory or with a contact probe (CP), which has the advantage of operating flexibility and the provision of repetitive in-situ reflectance measurements. Experiments comparing reflectance spectra measured with different devices and device settings are rarely reported in literature. Thus, in our study we focused on a comparison of spectra collected with two IS on identical samples ranging from a Spectralon and coloured papers as reference standards to vegetation samples with broadleaved (Nicotiana Rustica L.) and coniferous (Picea abies L. Karst.) leaf types. First, statistical measures such as mean absolute difference, median of differences,standard deviation and paired-sample t-test were applied in order to evaluate differences between collected reflectance values. The possibility of linear transformation between spectra was also tested. Moreover, correlation between normalised differential indexes (NDI) derived for each device and all combinations of wavelengths between 450 nm and 1800 nm were assessed. Finally, relationships between laboratory measured leaf compounds (total chlorophyll, carotenoids and water content), NDI and selected spectral indices often used in remote sensing were studied. The results showed differences between spectra acquired with different devices.
Permanent Link: http://hdl.handle.net/11104/0263371