BigFoot NPP Surfaces for North and South American Sites, 2000-2004

Each BigFoot NPP product covers a 7 x 7 km extent and consists of the NPP surface in ASCII Raster (BIL - Band Interleaved by Line) format (280 rows by 280 columns at 25 meter resolution) and an accompanying text file which provides metadata specific to the image (such as projection, data type, etc).Additional information on NPP surface development can be found on the BigFoot website at fsl.orst.edu/larse/bigfoot/ovr_mthd.html.BigFoot

Background

Reflectance data from MODIS, the Moderate Resolution Imaging Spectrometer onboard NASA's Earth Observing System (EOS) satellite Terra (landval.gsfc.nasa.gov/MODIS/index.php), is used to produce several science products including land cover, leaf area index (LAI), gross primary production (GPP) and net primary production (NPP). The overall goal of the BigFoot Project was to provide validation of these products. To do this, BigFoot combined ground measurements, additional high resolution remote sensing data, and ecosystem process models at nine flux tower sites representing different biomes to evaluate the effects of the spatial and temporal patterns of ecosystem characteristics on MODIS products.

BigFoot characterized up to a 7 x 7 km area (49 MODIS pixels) surrounding the CO2 flux towers located at each of the nine sites. We collected multi-year, in situ measurements of ecosystem structure and functional characteristics related to the terrestrial carbon cycle. Our sampling design allowed us to examine scales and spatial pattern of these properties, the inter-annual variability and validity of MODIS products, and provided for a field-based ecological characterization of the flux tower footprint.

BigFoot was funded by NASA's Terrestrial Ecology Program.For more details on the BigFoot Project, please visit the website: fsl.orst.edu/larse/bigfoot/index.html.