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United States National Aeronautics and Space Administration: Publications
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Full-Text Articles in Physical Sciences and Mathematics
Modis Snow-Cover Products, Dorothy K. Hall, George A. Riggs, Vincent V. Salomonson, Nicolo E. Digirolamo, Klaus J. Bayr
Modis Snow-Cover Products, Dorothy K. Hall, George A. Riggs, Vincent V. Salomonson, Nicolo E. Digirolamo, Klaus J. Bayr
United States National Aeronautics and Space Administration: Publications
On December 18, 1999, the Terra satellite was launched with a complement of five instruments including the Moderate Resolution Imaging Spectroradiometer (MODIS). Many geophysical products are derived from MODIS data including global snow-cover products. MODIS snow and ice products have been available through the National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) since September 13, 2000. MODIS snow-cover products represent potential improvement to or enhancement of the currently available operational products mainly because the MODIS products are global and 500-m resolution, and have the capability to separate most snow and clouds. The MODIS snow-mapping algorithms are …
Early Spatial And Temporal Validation Of Modis Lai Product In The Southern Africa Kalahari, J. L. Privette, R. B. Myneni, Y. Knyazikhin, M. Mukelabai, G. Roberts, Y. Tian, Y. Wang, S. G. Leblanc
Early Spatial And Temporal Validation Of Modis Lai Product In The Southern Africa Kalahari, J. L. Privette, R. B. Myneni, Y. Knyazikhin, M. Mukelabai, G. Roberts, Y. Tian, Y. Wang, S. G. Leblanc
United States National Aeronautics and Space Administration: Publications
We evaluate the operational MODIS Leaf Area Index (LAI) product using field-sampled data collected at five sites in southern Africa in March 2000. One site (Mongu, Zambia) was sampled monthly throughout the year. All sites were along the International Geosphere Biosphere Programme’s (IGBP) Kalahari Transect, which features progressively lower annual precipitation, and hence, lower vegetation productivity, from north to south. The soils are consistently sandy. At each site, we sampled the vegetation overstory along three 750-m transects using the Tracing Radiation and Architecture in Canopies (TRAC) instrument. The resulting plant area index values were adjusted with ancillary stem area data …
Global Products Of Vegetation Leaf Area And Fraction Absorbed Par From Year One Of Modis Data, R. B. Myneni, S. Hoffman, Y. Knyazikhin, J. L. Privette, J. Glassy, Y. Tian, Y. Wang, X. Song, Y. Zhang, G. R. Smith, A. Lotsch, M. Friedl, J. T. Morisette, P. Votava, R. R. Nemani, S. W. Running
Global Products Of Vegetation Leaf Area And Fraction Absorbed Par From Year One Of Modis Data, R. B. Myneni, S. Hoffman, Y. Knyazikhin, J. L. Privette, J. Glassy, Y. Tian, Y. Wang, X. Song, Y. Zhang, G. R. Smith, A. Lotsch, M. Friedl, J. T. Morisette, P. Votava, R. R. Nemani, S. W. Running
United States National Aeronautics and Space Administration: Publications
An algorithm based on the physics of radiative transfer in vegetation canopies for the retrieval of vegetation green leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR) from surface reflectances was developed and implemented for operational processing prior to the launch of the moderate resolution imaging spectroradiometer (MODIS) aboard the TERRA platform in December of 1999. The performance of the algorithm has been extensively tested in prototyping activities prior to operational production. Considerable attention was paid to characterizing the quality of the product and this information is available to the users as quality assessment (QA) accompanying the …
Multiscale Analysis And Validation Of The Modis Lai Product, Yuhong Tian, Curtis E. Woodcock, Yujie Wang, Jeff L. Privette, Nikolay V. Shabanov, Liming Zhou, Yu Zhang, Wolfgang Buermann, Jiarui Dong, Brita Veikkanen, Tuomas Häme, Kaj Andersson, Mutlu Ozdogan, Yuri Knyazikhin, Ranga B. Myneni
Multiscale Analysis And Validation Of The Modis Lai Product, Yuhong Tian, Curtis E. Woodcock, Yujie Wang, Jeff L. Privette, Nikolay V. Shabanov, Liming Zhou, Yu Zhang, Wolfgang Buermann, Jiarui Dong, Brita Veikkanen, Tuomas Häme, Kaj Andersson, Mutlu Ozdogan, Yuri Knyazikhin, Ranga B. Myneni
United States National Aeronautics and Space Administration: Publications
The development of appropriate ground-based validation techniques is critical to assessing uncertainties associated with satellite databased products. In this paper, the second of a two-part series, we present a method for validation of the Moderate Resolution Imaging Spectroradiometer Leaf Area Index (MODIS LAI) product with emphasis on the sampling strategy for field data collection. Using a hierarchical scene model, we divided 30-m resolution LAI and NDVI images from Maun (Botswana), Harvard Forest (USA) and Ruokulahti Forest (Finland) into individual scale images of classes, region and pixel. Isolating the effects associated with different landscape scales through decomposition of semivariograms not only …
First Operational Brdf, Albedo Nadir Reflectance Products From Modis, Crystal B. Schaaf, Feng Gao, Alan H. Strahler, Wolfgang Lucht, Xiaowen Li, Trevor Tsang, Nicholas C. Strugnell, Xiaoyang Zhang, Yufang Jin, Jan-Peter Muller, Philip Lewis, Michael Barnsley, Paul Hobson, Mathias Disney, Gareth Roberts, Michael Dunderdale, Christopher Doll, Robert P. D’Entremont, Baoxin Hu, Shunlin Liang, Jeffrey L. Privette, David P. Roy
First Operational Brdf, Albedo Nadir Reflectance Products From Modis, Crystal B. Schaaf, Feng Gao, Alan H. Strahler, Wolfgang Lucht, Xiaowen Li, Trevor Tsang, Nicholas C. Strugnell, Xiaoyang Zhang, Yufang Jin, Jan-Peter Muller, Philip Lewis, Michael Barnsley, Paul Hobson, Mathias Disney, Gareth Roberts, Michael Dunderdale, Christopher Doll, Robert P. D’Entremont, Baoxin Hu, Shunlin Liang, Jeffrey L. Privette, David P. Roy
United States National Aeronautics and Space Administration: Publications
With the launch of NASA’s Terra satellite and the MODerate Resolution Imaging Spectroradiometer (MODIS), operational Bidirectional Reflectance Distribution Function (BRDF) and albedo products are now being made available to the scientific community. The MODIS BRDF/Albedo algorithm makes use of a semiempirical kernel-driven bidirectional reflectance model and multidate, multispectral data to provide global 1-km gridded and tiled products of the land surface every 16 days. These products include directional hemispherical albedo (black-sky albedo), bihemispherical albedo (white-sky albedo), Nadir BRDF-Adjusted surface Reflectances (NBAR), model parameters describing the BRDF, and extensive quality assurance information. The algorithm has been consistently producing albedo and NBAR …