# ASTER Global Emissivity Dataset (AG100 V003)
*data products*

## Specifications
- **level**: L3
- **distributor**: usgs
- **spectral range nm**: {"min":8125,"max":11650}
- **spectral band count**: 5
- **gsd m**: {"native":100}
- **file format**: HDF5
- **access endpoint**: https://search.earthdata.nasa.gov
- **access model**: open
- **licence**: NASA EOSDIS open data (no restrictions on use or redistribution)
- **primary data portal url**: https://www.earthdata.nasa.gov/data/catalog/lpcloud-ag100-003
- **use cases**: ["Lithological discrimination of silicate rock assemblages using TIR emissivity contrasts across the 8-12 um reststrahlen region (quartz, feldspar, ultramafic)","Mineral exploration target generation independent of SWIR detector availability (TIR bands remained operational throughout the ASTER mission)","Regional geological mapping combining ASTER TIR emissivity with VNIR structural context and SWIR alteration signatures","Land surface temperature and emissivity input to evapotranspiration models (FAO SEBS, METRIC, SSEBop) at outcrop-to-watershed scale","Urban heat island characterisation and impervious surface emissivity mapping","Climate model land surface boundary condition validation (monthly composites via AG5KMMOH V041 companion product)"]
- **practical limitations**: ["Input archive spans 2000-2008 only; the product is a static climatological composite with no time-series dimension. Recent land cover or geological disturbance is not captured.","Spectral resolution is five discrete TIR bands, not a continuous TIR spectrum; mineral discrimination relies on band-ratio and spectral angle methods rather than full spectral library matching.","100 m spatial resolution resolves coarse lithological units; sub-outcrop-scale features below approximately 100-200 m are mixed-pixel responses.","NASA Earthdata account registration required for all access","HDF5 format requires pre-processing to extract per-band emissivity layers; no pre-packaged COG or STAC delivery as of 2026-05-19","Atmospheric correction uses MODIS MOD07_L2 profiles; accuracy is reduced in high-humidity tropical regions where atmospheric water vapour retrieval is less constrained."]
- **known artefacts**: ["AG5KMMOH monthly companion product: some months are missing due to outages in the MOD10CM snow-cover input dataset used in the WVS atmospheric correction. Version v041 is the current active version; v004 was decommissioned December 14, 2016.","Emissivity values in arid bare-soil regions are subject to higher uncertainty where surface mineralogy is highly variable and the multi-temporal composite contains few cloud-free acquisitions.","Desert quartz sand regions (Sahara, Arabian Peninsula) show very low emissivity in Band 12 (9.1 um); care required to distinguish geological quartz-arenite rock from aeolian sand when interpreting Band 12 minima."]
- **last verified date**: "2026-05-19T00:00:00.000Z"
- **verified by**: agency-doc
- **claim status**: agency-verified
- **deployment context**: orbital

## Compositional position
- minerals (topics) --[topic_capabilities]--> ASTER Global Emissivity Dataset (AG100 V003)

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Source: https://eo-atlas.org/data_products/aster-ged
Maintainer: SpectraWorks B.V. (CC-BY 4.0)