Where every number comes from.
Terra reads open data from space agencies, geological surveys and published research. Each source is listed here with its publisher, its licence and what Terra uses it for.
Sources in use.
Licences follow the source registry in the workbench and were last reviewed on 1 November 2026. Check the publisher's current terms before commercial use.
Satellite and terrain
- EMIT L2A reflectance and L2B mineral products
NASA JPL, LP DAAC
Imaging spectroscopy over arid ground: Al-OH, alunite, ferric iron and carbonate features.
Licence: NASA open data policy
- ASTER AST_07XT surface reflectance
NASA LP DAAC
Shortwave infrared band ratios and mineral indices, compared with EMIT where both cover an area.
Licence: NASA open data policy
- Sentinel-2 L2A
ESA Copernicus
Geolocation reference for every scene, iron oxide indices and masks.
Licence: Copernicus Sentinel data terms (free, full and open)
- Landsat 8 and 9 Collection 2 Level-2
USGS, NASA
Long time series and a second broadband reference.
Licence: U.S. public domain
- Copernicus DEM GLO-30
ESA Copernicus
Terrain, slope, shading and drainage.
Licence: Free, including commercial use, with attribution
Geology and geophysics
- EMAG2 magnetic anomaly grid
NOAA NCEI
Regional magnetic context where no survey exists.
Licence: U.S. public domain
- State Geologic Map Compilation (SGMC)
U.S. Geological Survey
Lithology and structure in the United States.
Licence: U.S. public domain
- Macrostrat geologic map units
University of Wisconsin-Madison
Geological units worldwide, with the original map sources cited.
Licence: CC BY 4.0
- Geoscience Australia surveys and maps
Geoscience Australia
Magnetics, gravity and the WASANT palaeovalley map used to check drainage analysis.
Licence: CC BY 4.0
Exploration history and geochemistry
- Mineral Resources Data System (MRDS)
U.S. Geological Survey
Recorded mines, prospects and occurrences.
Licence: U.S. public domain
- National Geochemical Database, rock samples
U.S. Geological Survey
Sample chemistry with detection limits, methods and media kept apart.
Licence: U.S. public domain
- BLM mining claims (MLRS)
U.S. Bureau of Land Management
Who held ground, and when.
Licence: U.S. public domain
- WAMEX, MINEDEX and WACHEM
Geological Survey of Western Australia
Exploration reports, drilling, mines and geochemistry in Western Australia.
Licence: Per dataset, stored with each import
- SARIG
Geological Survey of South Australia
Drillholes, geochemistry and mineral occurrences in South Australia.
Licence: Per dataset, stored with each import
- BC MINFILE and ARIS
Province of British Columbia
Occurrences and assessment reports in British Columbia.
Licence: Access only: used per search, never redistributed
Published research
- Howari et al. (2020), Wadi Ham copper study
Frontiers in Earth Science 8:578075
The reference for the experimental Wadi Ham workflow in the UAE. Cited, not digitised.
Licence: CC BY 4.0
How the work is checked.
What has been verified, and what has not, stated the same way in the workbench and in every report.
- 489 automated tests cover the calculations, the claims guard and the data imports.
- Spectral indices are checked against their published formulas, hand calculations and an independent implementation.
- EMIT and ASTER are compared at Cuprite and Goldfield, with a control pair that should not agree.
- Every result carries its source, version and evidence level; words such as discovered or confirmed are blocked before a report prints.
- No capability has had an external review yet. The Cuprite review package is ready for an outside reviewer.
Bring us the ground you are thinking about.
Name an area. We set up a pilot workspace with a first investigation and walk through it with you.