OT.082025.4674.1 en dataset OpenTopography info@opentopography.org distributor 2025-08-04 ISO 19139/19115 Metadata for Datasets 2003 SIRGAS 2000 [EPSG: 4674] WGS84 Ellipsoid/EGM2008 Geoid [EPSG: 3855] ANADEM: A Digital Terrain Model for South America 2025-08-04 publication <p><a href='https://metadados.snirh.gov.br/geonetwork/srv/eng/catalog.search#/metadata/93664c15-1ff8-4e87-bbed-2bb69d321309' target='_blank'>Agência Nacional de Águas DEM (ANADEM)</a>, is a Digital Terrain Model (DTM) for South America which removes the influence of vegetation on elevation values from the <a href='https://dataspace.copernicus.eu/explore-data/data-collections/copernicus-contributing-missions/collections-description/COP-DEM' target="_blank">Copernicus GLO-30 DEM</a> (COPDEM) by integrating remote sensing data, cloud computation, and machine learning techniques. ANADEM uses a vegetation bias removal algorithm that was specifically calibrated for South America, incorporating spectral indices from <a href='https://landsat.gsfc.nasa.gov/satellites/landsat-8/' target='blank'>Landsat-8</a> and <a href='https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-2' target='_blank'>Sentinel-2</a> (EVI, NDMI, MSAVI) combined with <a href='https://gedi.umd.edu/' target='_blank'>Global Ecosystem Dynamics Investigation</a> (GEDI) lidar data to improve vegetation bias removal in tropical and subtropical environments. The algorithm uses a TreeBoost machine learning model implemented in <a href='https://earthengine.google.com/' target='_blank'>Google Earth Engine</a>, trained with 50,000 samples per 5°×5° tile (with overlap) and 250 decision trees, allowing a fine-scale adjustment of vegetation bias corrections. ANADEM was validated against <a href='https://icesat-2.gsfc.nasa.gov/' target='_blank'>ICESat-2</a> altimetry data.</p> <p> For more details on this dataset, see its associated publication: <a href='https://doi.org/10.3390/rs16132321' target='_blank'>ANADEM: A Digital Terrain Model for South America</a> </p> <p><b>Note on Dataset Differencing:</b><br /> Users interested in comparing global DEMs (e.g., ANADEM, Copernicus GLO-30, NASADEM, ALOS, etc.) should be aware that differences in pixel size, grid alignment, and projection between datasets can introduce apparent artifacts when performing simple raster subtraction. To ensure accurate comparisons, we recommend reprojecting and resampling datasets to a common grid prior to differencing. This is a general best practice when working with any two globally-derived elevation products.</p> Universidade Federal do Rio Grande do Sul https://www.ufrgs.br/site/ custodian Agência Nacional de Águas e Saneamento Básico https://www.gov.br/ana/pt-br null info@opentopography.org https://opentopography.org distributor en geoscientificInformation -82.51655 -34.72655 -56.51552 14.07948 https://doi.org/10.5069/G9736P4G HTTP Standard Internet browser Download Navigate directly to the URL for data access and download.