Mapbox Terrain-DEM v1
This tileset reference document includes information to help you use the data in the Mapbox Terrain-DEM v1 tileset.
Overview
Mapbox Terrain-DEM v1 is a Mapbox-provided raster tileset is a global elevation layer. This tileset contains raw height values in meters in the Red, Green, and Blue channels of PNG tiles that can be decoded to raw heights in meters.
Mapbox Terrain-DEM is an optimized version of the Mapbox Terrain-RGB v1 tileset, with some updated data and some compression to reduce precision at lower zoom levels, making smaller, faster-loading tiles.
You can use Terrain-DEM for a wide variety of applications, both visual and analytical, from styling terrain slope and hillshades to generating 3D terrain meshes for video games.
Data sources and updates
Elevation data is not improved on a set schedule and is updated when and where it becomes available.
Attribution
When using this tileset publicly in a design or application you must provide proper attribution.
Terrain-RGB tiles
The Mapbox Terrain-DEM tileset contains Terrain-RGB tiles. Terrain-RGB tiles include elevation data that is encoded using each color channel as a position in a base-256 numbering system. This approach allows for 16,777,216 unique values which can be mapped to 0.1 meter height increments, enabling vertical precision necessary for cartographic and 3D applications.
To learn how to retrieve a Terrain-RGB tile and decode elevation data from its RGB values, see our Access elevation data guide.
Layer Reference
This tileset contains one layer with raster data.
- Data up to zoom 15. The data is encoded to the equivalent of zoom 15 at 256 tile resolution (and zoom 14 for 512 tiles). Any higher zoom levels will not increase the resolution of the data loaded by your application.
- 0.1 meter height increments. Elevation data is mapped to 0.1 meter height increments, which gives it the vertical precision necessary for cartographic and 3D applications.
- Buffered tiles. Each map tile includes a 1-pixel buffer around the edges to enable tile interpolation in uses cases like terrain meshes.
Elevation data
Mapbox Terrain-DEM uses multiple data sources depending on the zoom level and location. Different sources often use different vertical datum references, including but not limited to NAVD 88, EGM 96, and Ordnance Datum Newlyn.
Different sources often use different vertical datum references; thus, attempting to normalize Mapbox elevation data to a particular geoid or vertical datum may lead to inaccuracies in data.
After retrieving tiles via our one of our Mobile SDKs or Mapbox GL JS, you can use this equation to decode pixel values to height values:
height = -10000 + ((R * 256 * 256 + G * 256 + B) * 0.1)
For more details on accessing elevations from DEM tilesets, see the Access elevation data guide.
Changelog
- Dec 8, 2020 - Published the tileset.