Product | Sources | Precision | Accuracy |
---|---|---|---|
Land cover | NLCD (National Land Cover Database): developed from Landsat 30-m pixel; available for 1992, 2001, 2006, and 2011. U.S. only. | 20 classes | 78 and 79% for latest products [117] |
 | CORINE: developed from Landsat, Spot, and recently higher resolution imagery; available for 1990, 2000, 2006, 2012. Minimum mapping unit/with 25 ha/ 100 m. | 44 classes | 8% (for 2000 version) [131] |
 | MODIS Land Cover: available for 2001–2012, 500-m pixel resolution | 17 classes | 75% [132] |
 | GlobCover: based on 300-m pixel resolution imagery from MERIS sensor (ENVISAT), available for 2005–06 and 2009. | 23 classes | 58-79% [133] |
Terrain (elevation) | SRTM (Shuttle Radar Topography Mission): 30-m and 90-m pixel resolution | 16-bit | Geolocation error = 9.8 meters; absolute height error = 6.9 meters; relative height error = 7.0 meters [134] |
 | ASTER Global Digital Evalation Map: 30-m pixel | 16-bit | Overall accuracy ~17 meters [135] |
 | TanDem-X (TerraSAR-X add-on for Digital Elevation Measurement): provides elevation data <12-m pixel resolution; launched in 2010. | 16-bit | <2 m height accuracy [136] |
Climate/Weather | MODIS Land Surface Temperature/Emissivity: available daily, 8-day, and monthly, at 1-km, 5.6-km resolutions. | 8-bit and 16-bit | 0.5Â K to 1Â K [132] |
 | TRMM (Tropical Rainfall Measuring Mission): 16 times per day, multiple products describing rainfall at 2.4 km and 5-km pixel resolution | na | TRMM Precipitation Radar instrument is able to detect fairly light rain rates down to about .0.7 mm per hour. |
 | MODIS Cloud Product: daily product of cloud properties at 1-km and 5-km pixel resolution. | na | na |
Phenology | MODIS Global Vegetation Phenology product (MCD12Q2): provides estimates of the timing of vegetation phenology at 500-m pixel resolution. MCD12Q2 is produced once a year with 24 months of input data, available from 2001 through 2012 | 16-bit | Consistent with in-situ measurements [137] |
 | SPOT Vegetation: provides NDVI global data since 1998 at a 1.15-km pixel resolution | na | na |
 | MODIS Gross Primary Productivity (GPP) product (MOD17A2): 8-day composite at 1-km spatial resolution | 8-bit and 16-bit | Annual estimates of GPP are within 10.4% of average published results [132] |
 | MODIS Leaf Area Index (LAI) and Fractional Photosynthetically Active Radiation (FPAR): 8-day composite at 1-km spatial resolution | 8-bit | Accuracy is 0.66 LAI units RMSE and 0.12 FPAR units RMSE respectively [132] |