The Land Surface Reflectance Science Computing Facility is
responsible for producing the MODIS Surface Reflectance product (MOD09).
MODIS Surface Reflectance is a seven-band product computed from the
MODIS Level 1B land bands 1, 2, 3, 4, 5, 6, and 7. The product is an
estimate of the surface spectral reflectance for each band as it would
have been measured at ground level as if there were no atmospheric
scattering or absorption. It corrects for the effects of atmospheric
gases, aerosols, and thin cirrus clouds. The surface reflectance is
inverted with the help of a radiative transfer model (http://modis-sr.ltdri.org/code.html)
using atmospheric inputs taken from NCEP (ozone, pressure) or directly
derived the MODIS data (aerosol, water vapor).
Surface Reflectance product is a major input utilized in the generation
of several land products: Vegetation Indices, BRDF, Land Cover, Snow
Cover, Thermal Anomalies, and LAI/FPAR.
For stage II validation, the accuracy of the surface reflectance has
been evaluated for 157367 cases for TERRA and 118195 cases for AQUA; the product performs well since
approximately 90% of the data are within the theoretical errors
bars (click on the figure for more information).
Terra 2002-2009 Validation Results
Aqua 2002-2009 Validation Results