What are the World Elevation services?

Note:

BETA NOTE: Access to the World Elevation services is limited during beta. If you want to join, sign up with Esri's Beta Community World Elevation Services beta program.

The World Elevation services provide effortless, online access to global collections of multiresolution, multisource elevation data. This collection includes data with resolutions ranging from over 200 km to less than 1 meter. The services provide a single endpoint for desktop and web applications to access elevation values and derived products.

You can use it in your desktop and web applications

• For visualization or analysis
• As information layers, such as a hillshade or aspect
• To orthorectify imagery
• As a data source in your analysis models or other geoprocessing tasks
• To obtain data locally

For visualization

The image services that are provided for visualization can be used as base images in your Desktop applications, such as ArcMap, to support the other data. They are also recommended for any web applications since they're already optimized for displaying. The recommended services include the hillshade, tinted hillshade, slope, and aspect rendered versions of the source elevation data.

The hillshaded image service has a smaller bit depth (8-bit) than the source DEM (32-bit). Therefore, if you want to use the image service in a visual capacity and not for processing, it's faster to transmit the smaller bit-depth data than the larger, source DEM. Also, the source DEM will need to be processed by your application; which will add to the display time.

There are two available versions of the hillshade: a DTM and DSM hillshade. The DTM hillshade is generated from a DEM that defines the ground surface. Heights are orthometric and sea level = 0. The DSM hillshade is generated from the DEM that defines the first return surface elevation values (includes features, such as building tops, bridges, and tree canopies). The DSM hillshade is ideal for large-scale needs in the areas where this type of data is available. There is also a color tinted hillshade, created from the DTM.

DTM hillshade

DSM Hillshade

The slope and aspect image services for visualization have been rendered with color and the bit depth has been modified to represent the color values, not the slope or aspect values. Similarly to the hillshade, this reduced bit depth should display faster than the image service with the actual or processed values.

DTM Slope

DTM Aspect

For analysis

The image services that are provided for analysis can be used by applications that will either use the image service as a source for their own analysis, or to use the elevation data to process other imagery, such as performing an orthorectification. The recommended services for analysis include two versions of a DEM, slope, and aspect.

Note:

When using these image services in geoprocessing tools, use the Make Image Server Layer tool to define some of the properties of the image service, such as the extent and band number. Remember that the size of the output layer is also limited by the request size property of the image service--which is 4000 x 4000 pixels. To learn more, see Using mosaic datasets and image services in geoprocessing tools.

Image services

These image services are available on ArcGIS Online. You can access them individually or search for the World Elevation group to access the entire collection.

Name	Description	For Visualization	For Analysis
World Digital Terrain Model (DTM)	A digital elevation model (DEM) that defines the ground surface. Heights are orthometric and sea level = 0.	No (generally)	Yes
World Digital Surface Model (DSM)	A DEM that defines the first return surface elevation values (includes features such as building tops, bridges, and tree canopies).	No (generally)	Yes
World Elevation DTM Hillshade	A grayscale hillshade created from the DTM.	Yes	No
World DTM Elevation Tinted Hillshade	A tinted hillshade surface created from the World Digital Terrain Model.	Yes	No
World Elevation DSM Hillshade	A grayscale hillshade created from the DSM.	Yes	No
World Elevation Aspect Map	Aspect generated from the DTM. Rendered with color such that the orientation of the downward sloping terrain is indicated by different colors, rotating from green to blue to red to yellow (clockwise from north).	Yes	No
World Elevation Aspect	Aspect generated from the DTM. Values represent the orientation of the downward sloping terrain as 0 to 360 degrees.	No	Yes
World Elevation Slope Map	Slope generated from the DTM. Rendered with color to represent flat to steep slope (green to red).	Yes	No
World Elevation Slope	Slope generated from the DTM. Values represent the angle of the downward sloping terrain from 0 to 90 degrees.	No	Yes
World Elevation Surface Height	Surface heights based on subtracting the ground elevation from the highest available surface heights.	No	Yes
World DTM Ellipsoidal	Digital terrain model (DTM) of ground surface heights representing ellipsoidal measurements calculated by adding the EGM2008 geoid model.	No	Yes
World TopoBathy Hillshade	Hillshaded surface created from ground height topography and bathymetry measurements.	Yes	No
World TopoBathy Elevation Tinted Hillshade	A tinted hillshade surface created from ground height topography and bathymetry measurements.	Yes	No

Sources

The source elevation data is comprised of the best publically available elevation data and some samples from commercial vendors. The table below provides a list of sources contributing data to the World Elevation services.

If you have data you wish to contribute, contact [e-mail].

Sources	Data	Approximate Cell Size (m)
www.oregonmetro.gov	Portland lidar DEM	0.9
www.intermap.com	Intermap DEM	4.6
www.usgs.gov	NED 2, 1, 1/3rd, 1/9th Arc Second DEM	62 - 3.1
www.usgs.gov www.cgiar-csi.org www.nasa.gov	SRTM DEM	93
www.usgs.gov	GMTED DEM	232
www.bodc.ac.uk	GEBCO Bathymetry	928
earth-info.nga.mil	EGM2008	4638

Data sources