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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.

Version Description

Version 1

Product Summary

Platforms
OV-105
Instruments
SRTM
Spatial Extent
N: 60 S: -56 E: 180 W: -180
Spatial Resolution
30 Meters x 30 Meters
Geographic Region
GLOBAL LAND
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2000-02-11 to 2000-02-21
Temporal Resolution
11 Day
Data Partner
Land Processes Distributed Active Archive Center (LP DAAC)
Shuttle Radar Topography Mission Project Office, Jet Propulsion Laboratory, NASA (NASA/JPL/SRTM)
Concept ID
C2763264762-LPCLOUD
Data State
COMPLETE
Processing Level
3
Published
Updated
Science Keywords
Terrain Elevation,
RADAR IMAGERY,
Topographical Relief Maps

Citation

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.

Copy Citation

NASA JPL. (2020). NASADEM Merged DEM Global 1 arc second V001 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MEASURES/NASADEM/NASADEM_HGT.001 Date Accessed: 2025-10-21

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).

Documents

Publications Citing This Dataset

Filters
Title Year Author
Estimating building height in China from ALOS AW3D30 Huang, H. B.
Granularity of digital elevation model and optimal level of detail in small-scale cartographic relief presentation Samsonov, T.
Mathematical vector framework for gravity-specific land surface curvatures calculation from triangulated irregular networks Hu, G. H.
Rapid glacier mass loss in the Southeastern Tibetan Plateau since the year 2000 from satellite observations Zhao, F.
An area-based projection algorithm for SAR radiometric terrain correction and geocoding Shiroma, G. H. X.
Dynamic forecast of desert locust presence using machine learning with a multivariate time lag sliding window technique Sun, R.
Free global DEMs and flood modelling—A comparison analysis for the January 2015 flooding event in Mocuba City (Mozambique) Garrote, J.
Large landslides cluster at the margin of a deglaciated mountain belt Pánek, T.
Anopheles albimanus (Diptera: Culicidae) ensemble distribution modeling—Applications for malaria elimination Rhodes, C. G.
Estimation of aerosol optical depth at 30 m resolution using Landsat imagery and machine learning Liang, T. C.
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Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
DEM Void-filled DEM Meters int16 N/A N/A to 32767 N/A
NUM Number of scenes Class uint8 N/A N/A to 255 N/A
SWB Updated SRTM water body data Class uint8 N/A N/A to 255 N/A
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