Abstract:
The MODIS Surface Reflectance products are an estimate of the surface spectral
reflectance as it would be measured at ground level in the absence of
atmospheric scattering or absorption. Low-level data are corrected for
atmospheric gases and aerosols, yielding a level-2 basis for several
higher-order gridded level-2 (L2G) and level-3 products.
...
The MOD09Q1 product provides Band 1 and 2 data at a 250-meter resolution in an
8-day gridded level-3 product in the Sinusoidal projection. Each MOD09Q1 pixel
contains the best possible L2G observation during an 8-day period as selected
on the basis of high observation coverage, low view angle, the absence of
clouds or cloud shadow, and aerosol loading. Science Data Sets provided for
this product include reflectance values for Bands 1 and 2, and a quality
rating.
Data Set Characteristics:
Area: ~10 degrees x 10 degrees lat/long
Image Dimensions: 4800 x 4800 rows/columns
File Size: ~72 MB compressed
Resolution: 250 meters
Projection: Sinusoidal
Data Format: HDF-EOS
Science Data Sets (SDS HDF Layers): 3
Version-5 MODIS/Terra Surface Reflectance products are validated, meaning that
product uncertainties are well defined over a range of representative
conditions. Although there may be later improved versions, these data are ready
for use in scientific publications. 
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