EOS Validation Program

Institution: USGS/EROS Data Center
Phone: (605) 594-6046
E-mail: meyer@edcsns1e.cr.usgs.gov

Larry Tieszen, EROS Data Center
Wayne Boncyk, EROS Data Center
Louis Steyaert, EROS Data Center
Greg Zylstra, EROS Data Center

A method of the validation of surface quantities (reflection, LAI and fAPAR), proposed here, uses more spatially extensive field sampling patterns, coupled with geostatistical methods for quantifying errors due to spatial undersampling, and higher resolution satellite images to assist scaling the surface relationships to lower resolution satellites data such as that from MODIS. The method is designed to measure areas which are extensive compared to the MODLAND tier-3 biome tower concept. and hence complements these towers by capturing the range of variability of both reflectance and biophysical quantities within the grassland biome. With concurrent atmospheric radiation measurements, it is also possible to validate atmospherically-corrected MODIS surface reflectance products which are used by the MODIS LAI and fAPAR algorithms. The methodology allows for an intercomparison between the Landsat-7 ETM+, and the MODIS instrument itself. The fAPAR and LAI measurements are made in a manner completely distinct from the algorithms used to generate the corresponding MODIS products, comprising an independent validation over grasslands.