The ASTER Global Emissivity Dataset (ASTER GED): Mapping Earth's emissivity at 100 meter spatial scale

Thermal infrared (TIR) data, acquired by instruments on several NASA satellite platforms, are primarily used to estimate the surface temperature/emissivity of the Earth's land surface. One such instrument launched on NASA's Terra satellite in 1999 is the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which has a spatial resolution of 90 m. Using ASTER data, NASA/Jet Propulsion Laboratory recently released the most detailed emissivity map of the Earth termed the ASTER Global Emissivity Dataset (ASTER GED) that was acquired by processing millions of cloud free ASTER scenes from 2000 to 2008. The ASTER GEDv3 provides an average emissivity at ~100 m and ~1 km, while GEDv4 provides a monthly emissivity from 2000 to 2015 at ~5 km spatial resolution in the wavelength range between 8 and 12 µm. Validation with lab spectra from four desert sites resulted in an average absolute band error of ~1%, compared to current heritage MODIS products that had average absolute errors of 2.4% (Collection 4) and 4.6% (Collection 5).