ASTER Global Emissivity Dataset (AG100 V003)

ASTER Global Emissivity Dataset (AG100 V003) is a static 100-metre-resolution thermal infrared emissivity product derived from ASTER acquisitions collected between 2000 and 2008 aboard the Terra satellite.^[1][2] Five TIR bands spanning 8.125 to 11.65 um are composited into a multi-temporal average using a water-vapour-scaled algorithm described by Hulley et al. (2015) that applies MODIS MOD07_L2 atmospheric profiles for correction.^[3] The product is distributed by LP DAAC via NASA Earthdata as HDF5 files under an open EOSDIS licence with no restrictions on use or redistribution.^[1]

Because the ASTER TIR subsystem remained operational throughout the full mission, the product is the broadest spaceborne archive of per-band surface emissivity in the 8-12 um reststrahlen region. Primary applications include lithological discrimination of silicate rock assemblages (quartz, feldspar, ultramafic), hydrothermal alteration mapping, and land surface temperature retrieval as input to evapotranspiration models such as FAO SEBS and METRIC.^[1] Urban heat island and impervious surface characterisation are secondary use cases at outcrop-to-watershed scale.^[1]

The product is a climatological composite with no time-series dimension; land cover or geological change after 2008 is not represented. Spatial resolution of 100 m resolves coarse lithological units but mixes sub-outcrop-scale features. Atmospheric correction accuracy is reduced in high-humidity tropical regions where MODIS water vapour retrieval is less constrained.^[3] HDF5 delivery requires pre-processing to extract per-band emissivity layers; no pre-packaged COG or STAC endpoint is available as of May 2026.^[1] The monthly AG5KMMOH companion product carries gaps in months where the MOD10CM snow-cover input was unavailable; V003 of that companion product was decommissioned December 2016.^[4]