== DATATSET == Description GIMMS VIIRS NPP Global Cloud Optimized GeoTiff Coverage Global 180W to 180E, 81N to 63S Projection Lat/Lon grid Spatial Res. 0.0045 x 0.0045 degrees File Format Cloud Optimized GeoTIFF (COG) Download https://gimms.gsfc.nasa.gov/VIIRS/ == NEAR REAL-TIME AND STANDARD PROCESSING == Forward near real-time (nrt) processing of this dataset is available within 12 hours from the last day of the 8-day composite period. Science quality, standard (std) processing is typically available one or more days after the last day of the 8-day composite period. The two processing modes differ in their ephemeris and production rules [1]. Processing Data Source ---------- ----------- nrt LANCE near real-time std MODAPS science quality * GIMMS nrt datasets are only available for 30 days after production. [1] https://earthdata.nasa.gov/earth-observation-data/near-real-time/near-real-time-versus-standard-products == FILE NAMING == For example, GVNP09H1.A2012017.08d.latlon.global.001.NDVI.tif Qualifier Value Description --------- ----- ----------- Dataset GVNP09H1 GIMMS VIIRS NPP Start date A2012017 Starting year 2012 & day-of-year 017 Composite period 08d 8-day composite Projection latlon Lat/Lon grid Coverage global Global land 180W-180E, 81N-63S Collection 001 MODAPS collection 1 Layer name NDVI Normalized Vegetation Index File format tif Tagged Image File == PROJECTION == This dataset is mapped to a global 180W to 180E, 81N to 63S Lat/Lon grid. Coordinates are mapped and measured from the upper left corner of the grid cell. Parameter Value Units --------- ----- ----- Datum WGS84 - Upper left Lat 81.0 deg Upper left Lon -180.0 deg Pixel size 0.0045 deg Grid x size 80000 pixel Grid y size 32000 pixel == LAYERS == The valid range of the NDVI, NDVI_mean, NDVI_anom, and NDVI_pasg layers is [0 - 250]. Layer Name Datatype Valid Range ---------- -------- ----------- NDVI 8-bit UINT [0 - 250] NDVI_mean 8-bit UINT [0 - 250] NDVI_anom 8-bit UINT [0 - 250] NDVI_pasg 8-bit UINT [0 - 250] For NDVI, NDVI_mean, NDVI_anom, and NDVI_pasg 8-bit layers, values [251 - 255] are reserved for mask values: Value Description ----- ----------- 251 Snow/ice 252 Cloud 253 Invalid (out of range NDVI or NDVI_anom) 254 Water 255 No data (unfilled) The NDVI 8-bit layer only includes positive NDVI units [0.0 - 1.0]. To convert from NDVI 8-bit unsigned integer [0 - 250] to floating-point [0.0 - 1.0]: = x 0.004 To convert from NDVI_anom 8-bit unsigned integer [0 - 250] to floating-point [-1.0 - 1.0]: = ( - 125) x 0.008 NDVI_pasg values [0 - 250] represents PASG values 0% to 250%. == PROJECT == USDA/FAS/IPAD NASA/GSFC/GIMMS Global Agricultural Monitoring Project https://ipad.fas.usda.gov/glam.aspx https://glam1.gsfc.nasa.gov/api/doc/about == ACKNOWLEDGMENT == The GIMMS Global Agricultural Monitoring system is funded through an interagency agreement grant between USDA/FAS/OGA and NASA/GSFC. We request users of data products obtained herein to include a general statement crediting the NASA/GSFC GIMMS Group and the USDA Foreign Agricultural Service in written articles or presentations. For example, The Visible Infrared Imaging Radiometer Suite (VIIRS) Normalized Difference Vegetation Index (NDVI) used in this study was processed and produced by the NASA/Goddard Space Flight Center’s Global Inventory Modeling and Mapping Studies (GIMMS) Group through funding support of the Global Agricultural Monitoring project by USDA's Foreign Agricultural Service (FAS). == DISCLAIMER == The information presented through GIMMS/GLAM are provided "as is" and users bear all responsibility and liability for their use of data, and for any loss of business or profits, or for any indirect, incidental or consequential damages arising out of any use of, or inability to use, the data. The GIMMS Group has no obligations to provide maintenance and support. == HISTORY == Last updated 2023-07-28