Retrieval and validation of forest background reflectivity from daily Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF) data across European forests

0542569 - ÚVGZ 2022 RIV DE eng J - Článek v odborném periodiku
Pisek, J. - Erb, A. - Korhonen, L. - Biermann, T. - Carrara, A. - Cremonese, E. - Cuntz, M. - Fares, S. - Gerosa, G. - Gruenwald, T. - Hase, N. - Heliasz, M. - Ibrom, A. - Knohl, A. - Kobler, J. - Kruijt, B. - Lange, H. - Leppanen, L. - Limousin, J.-M. - Lopez Serrano, F. R. - Loustau, D. - Lukeš, Petr - Lundin, L. - Marzuoli, R. - Molder, M. - Montagnani, L. - Neirynck, J. - Peichl, M. - Rebmann, C. - Rubio, E. - Santos-Reis, M. - Schaaf, C. - Schmidt, M. - Simioni, G. - Soudani, K. - Vincke, C.
Retrieval and validation of forest background reflectivity from daily Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF) data across European forests.
Biogeosciences. Roč. 18, č. 2 (2021), s. 621-635. ISSN 1726-4170. E-ISSN 1726-4189
Výzkumná infrastruktura: CzeCOS III - 90123
Institucionální podpora: RVO:86652079
Klíčová slova: albedo product mcd43a * leaf-area index * understory reflectance * seasonal dynamics * operational brdf * boreal forests * vegetation * surface * definitions * utility
Obor OECD: Environmental sciences (social aspects to be 5.7)
Impakt faktor: 5.092, rok: 2021
Způsob publikování: Open access
https://bg.copernicus.org/articles/18/621/2021/

Information about forest background reflectance is needed for accurate biophysical parameter retrieval from forest canopies (overstory) with remote sensing. Separating under- and overstory signals would enable more accurate modeling of forest carbon and energy fluxes. We retrieved values of the normalized difference vegetation index (NDVI) of the forest understory with the multi-angular Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF)/albedo data (gridded 500 m daily Collection 6 product), using a method originally developed for boreal forests. The forest floor background reflectance estimates from the MODIS data were compared with in situ understory reflectance measurements carried out at an extensive set of forest ecosystem experimental sites across Europe. The reflectance estimates from MODIS data were, hence, tested across diverse forest conditions and phenological phases during the growing season to examine their applicability for ecosystems other than boreal forests. Here we report that the method can deliver good retrievals, especially over different forest types with open canopies (low foliage cover). The performance of the method was found to be limited over forests with closed canopies (high foliage cover), where the signal from understory becomes too attenuated. The spatial heterogeneity of individual field sites and the limitations and documented quality of the MODIS BRDF product are shown to be important for the correct assessment and validation of the retrievals obtained with remote sensing.
Trvalý link: http://hdl.handle.net/11104/0319955