Aster GDEM

Free

Providers: NASA (USA) & METI (Japan)
Mission Platform: Terra Satellite
Sensor: ASTER (Visible and Near-Infrared VNIR Sensor)
Release Version: Version 3 (latest, released in 2019)

Specification

Coverage Area : Global (83°N to 83°S) — nearly full land coverage

Spatial Resolution : 1 arc-second (~30 meters at the equator)

Vertical Accuracy : ±20 m (RMSE globally), varies by terrain and land cover

Horizontal Datum : WGS 84 (EPSG:4326)

Vertical Datum : EGM96 geoid

File Format : GeoTIFF

Tile Size  : 1° x 1°

Elevation Units : Meters above mean sea level

Data Type : 16-bit signed integer

Data Source : Optical stereo imagery from ASTER VNIR nadir and backward-looking bands

Data Collection Period : 2000 – 2011 (GDEM V2), updated through 2019 (GDEM V3)

Void Filling:  Interpolation using neighboring data and averaging from multiple scenes

Scenes per Pixel : Up to 30 stereo pairs used per location (V3), improving quality and reducing artifacts

Access / Licensing : Free and open access via NASA Earthdata or LP DAAC