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EDG Data Set Name Granule Shortname
MODIS/Terra Surface Reflectance Quality Daily L2G Global 1km SIN Grid MOD09GST

Version Acquisition Range Science Quality Status
V003 August 29, 2002 (2002241) - October 7, 2002 (2002280) Provisional as of Nov 1, 2000
V004 February 24, 2000 (2000055) Validated Stage 1 as of January 1 2003



Data Set Characteristics
Area = ~ 10° x 10° lat/long
Image Dimensions = 2 (1200x1200 row/column)
Average File Size = 9 MB
Resolution = ~1000 meters
Projection = Sinusoidal
Data Format = HDF-EOS
Science Data Sets (SDSs) = 3
MODIS Product
RGB of MOD09 surface reflectance (Northern Mexico, southwest US. 4/14/2000)
MODIS Product
Corresponding information from MOD09GST (see table for color code)
color cloud value land/sea value
magenta [undefined] [undefined]
violet clear shallow ocean
yellow cloudy shallow ocean
green clear land
red cloudy land
white clear coastlines/shorelines
coral cloudy coastlines/shorelines
plum cloudy shallow inland water
cyan cloudy ephemeral water
blue clear continental/moderate ocean
sienna cloudy continental/moderate ocean

Product Description
The MODerate-resolution Imaging Spectroradiometer (MODIS) Surface Reflectance products are computed from bands 1-7 to provide an estimate of the surface spectral reflectance for each band as it would be measured at ground level in the absence of atmospheric scattering or absorption. A correction scheme identifies atmospheric gases, aerosols, and thin cirrus clouds.

The MODIS/Terra Surface Reflectance State Daily L2G Global 1km SIN Grid product, MOD09GST, is a restructured version of the quality data in level-2 surface reflectance. MOD09GST summarizes the quality of the MOD09 products, including atmospheric and other correction states. The product specifically contains information pertaining to cloud and cloud shadow, land and water designations, aerosols, and the data source of corrections performed on the file. MOD09GST contains three Science Data Sets (SDSs); reflectance data state quality assurance, the number of observations, and observation coverage for each pixel.

The table above interprets the colors used to display the MOD09GST Surface Reflectance Data State product over Tile h08v06 covering northern Mexico on April 4, 2000. A corresponding MOD09GHK surface reflectance product is also shown for reference. Level-2G surface reflectance data are input for the generation of several land products: 8-day Surface Reflectance, Vegetation Indices (VIs), Bidirectional Reflectance Distribution Function (BRDF), thermal anomaly, snow/ice, and Fraction of Photosynthetically Active Radiation/Leaf Area Index (FPAR/LAI).

NOTE: These 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

SDS Units Data Type-bit Fill Value Valid Range
*1km Reflectance Data State QA Bit field 16-bit unsigned integer 65535 0 - 65535
Orbit and coverage Bit field 8-bit unsigned integer 15 0 – 255
Number of Observations na 8-bit signed integer -1 0 - 127


*MODIS Surface Reflectance QA Science Data Sets

View a Version Formatted for Printing

Retrieve the MOD09GSTv4 MODIS product through the LP DAAC Data Pool
Via Search Tool: http://e4eil01u.ecs.nasa.gov:22000/WebAccess/drill?attrib=esdt&esdt=MOD09GST.4&group=MOLT
Via FTP Directory: ftp://e4ftl01u.ecs.nasa.gov/MOLT/MOD09GST.004/

New! Order These Data through the EOS Data Gateway
MODIS/TERRA SURFACE REFLECTANCE QUALITY DAILY L2G GLOBAL 1KM SIN GRID V004

EOS Data Gateway Search Tips

Data Center: LPDAAC
Sensor: MODIS
Dataset: MODIS/Terra Surface Reflectance Quality Daily L2G Global 1km SIN Grid
Spatial: HORIZONTALTILENUMBER Max/Min VERTICALTILENUMBER Max/Min
Geographic Extent: Type Lat/Long Range or Draw on Map
Temporal Extent: 2000-02-24 to present

Product Information
Product Description
(http://landval.gsfc.nasa.gov/MODLAND/surfrad.htm)
User Guide
(http://modis-sr.ltdri.org/html/surfref.htm)
Algorithm Theoretical Basis Document (ATBD)
(http://modis.gsfc.nasa.gov/data/atbd/atbd_mod08.pdf)
MODIS Standard Data Products Catalog
(http://modis.gsfc.nasa.gov/data/dataprod/index.php)
EOS Data Products Handbook Volume 1 (2000)
(http://eospso.gsfc.nasa.gov/eos_homepage/for_scientists/data_products/vol1.php)

Contact Information
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Last Update: Tuesday, August 30, 2005
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