ANADEM: a bare-earth Digital Terrain Model for South America at ~30 m resolution, produced by the Federal University of Rio Grande do Sul (UFRGS/IPH) with the Brazilian National Water and Sanitation Agency (ANA).
Source & method: A true Digital Terrain Model (DTM) — it removes the vegetation bias from the Copernicus DEM GLO-30 surface model with a machine- learning correction calibrated specifically for South America, combining Landsat-8 / Sentinel-2 spectral indices (EVI, NDMI, MSAVI) with GEDI spaceborne- lidar ground elevations.
Resolution: 30 m nominal, on a single continent-wide mosaic (one item, not tiled).
Coordinate reference: Geographic SIRGAS 2000 (EPSG:4674 — WGS84-equivalent at this resolution); elevations in meters on the EGM2008 geoid (EPSG:3855).
Hosting: The asset references the public, anonymously readable Cloud-Optimized GeoTIFF on OpenTopography (opentopography.s3.sdsc.edu) in place — Darly does not re-host or copy the pixels.
Coverage: Continental South America (82.5°W–31.9°W, 56.8°S–14.1°N).
Version: v1 (current). New non-breaking versions overwrite this mosaic in place; a breaking change (different resolution/CRS/datum) would get its own collection.
Documentation:
Access
The catalog is browsable without a key. Elevation lookups need a free API key, sent as an X-API-Key header; see the quickstart.
curl "https://api.darly.io/collections/sam-ufrgs-anadem-30m/items?limit=5"curl -H "X-API-Key: $DARLY_API_KEY" \
"https://api.darly.io/v1/elevation/point?lat=-21.34&lon=-57.2&collections=sam-ufrgs-anadem-30m"from pystac_client import Client
catalog = Client.open("https://api.darly.io")
search = catalog.search(collections=["sam-ufrgs-anadem-30m"], bbox=[-82.52, -56.76, -31.89, 14.08], max_items=5)
for item in search.items():
print(item.id, item.assets["dtm"].href if "dtm" in item.assets else item.assets["dsm"].href)Providers
- Universidade Federal do Rio Grande do Sul (UFRGS/IPH) — producer, processor, licensor
- Agência Nacional de Águas e Saneamento Básico (ANA) — producer
- OpenTopography — host
- Darly — processor
Citation
Laipelt, L.; Andrade, B.C.; Collischonn, W.; Teixeira, A.A.; Paiva, R.C.D.; Ruhoff, A. (2024). ANADEM: A Digital Terrain Model for South America. Remote Sensing, 16(13), 2321.