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Description
The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) Digital Elevation Model (DEM) version 1 (NASADEM_HGT) dataset, which provides global elevation data at 1 arc second spacing.
NASADEM data products were derived from original telemetry data from the Shuttle Radar Topography Mission (SRTM), a collaboration between NASA and the National Geospatial-Intelligence Agency (NGA), as well as participation from the German and Italian space agencies. SRTM's primary focus was to generate a near-global DEM of the Earth using radar interferometry. It was a primary component of the payload on space shuttle Endeavour during its STS-99 mission, which was launched on February 11, 2000, and flew for 11 days.
In addition to Terra Advanced Spaceborne Thermal and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) Version 2 data, NASADEM also relied on Ice, Cloud, and Land Elevation Satellite (ICESat) Geoscience Laser Altimeter System (GLAS) ground control points of its lidar shots to improve surface elevation measurements that led to improved geolocation accuracy. Other reprocessing improvements include the conversion to geoid reference and the use of GDEMs and Advanced Land Observing Satellite Panchromatic Remote-sensing instrument for Stereo Mapping (PRISM) AW3D30 DEM, and interpolation for void filling.
NASADEM are distributed in 1 degree latitude by 1 degree longitude tiles and consist of all land between 60° N and 56° S latitude. This accounts for about 80% of Earth's total landmass.
NASADEM_HGT data product layers include DEM, number of scenes (NUM), and an updated SRTM water body dataset (water mask). The NUM layer indicates the number of scenes that were processed for each pixel and the source of the data. A low-resolution browse image showing elevation is also available for each NASADEM_HGT granule.
The global 1 arc second NASADEM product is also available in NetCDF4 format as the NASADEM_NC dataset with the source of each elevation pixel in the corresponding NASADEM_NUMNC product.
Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.
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Citation Copied
NASA JPL. (2020). NASADEM Merged DEM Global 1 arc second V001 [Dataset]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MEASURES/NASADEM/NASADEM_HGT.001 Date Accessed: 2026-08-12
Generator: [DEM Net Elevation API](https://elevationapi.com) Digital Elevation Model: [NASADEM](https://doi.org/10.5067/MEaSUREs/NASADEM/NASADEM_HGT.001) Imagery: [Esri World Imagery](https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer) Data: [OpenStreetMap](http://www.openstreetmap.org)
NASA JPL. (2020). NASADEM Merged DEM Global 1 arc second V001 [Dataset]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MEASURES/NASADEM/NASADEM_HGT.001 Date Accessed: 2026-08-12
NASA JPL. “NASADEM Merged DEM Global 1 Arc Second V001.” NASA Land Processes Distributed Active Archive Center, 2020, https://doi.org/10.5067/MEASURES/NASADEM/NASADEM_HGT.001. Date Accessed: 2026-08-12
File Naming Convention
s01w047.hgt
The file name begins with the latitude and longitude of the lower left corner of the tile (s01w047) followed by the File Extension/Variable (hgt).
The table below lists the variables contained within a single granule for this
dataset. Variables often contain observed or derived geophysical measurements
collected from a variety of sources, including remote sensing instruments on
satellite and airborne platforms, field campaigns, in situ measurements, and
model outputs. The terms variable, parameter, scientific data set, layer, and band
have been used across NASA’s Earth science disciplines; however, variable is the
designated nomenclature in NASA’s Common Metadata Repository (CMR).
Variable metadata attributes such as Name, Description, Units, Data Type, Fill
Value, Valid Range, and Scale Factor allow users to efficiently process and analyze
the data. The full range of attributes may not be applicable to all variables.
Additional information on variable attributes is typically available in the data,
user guide, and/or other product documentation.
For questions on a specific variable, please use the Earthdata Forum.