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NASA Shuttle Radar Topography Mission Global 3 arc second number V003

Metadata Updated: December 6, 2023

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) (https://earthdata.nasa.gov/community/community-data-system-programs/measures-projects) SRTM, which includes the global 3 arc second (~90 meter) number product.

Ancillary one-byte (0 to 255) “NUM” (number) files were produced for NASA SRTM Version 3. These files have names corresponding to the elevation files, except with the extension “.NUM” (such as N37W105.NUM). The elevation files use the extension “.HGT”, meaning height (such as N37W105.HGT). The separate NUM file indicates the source of each DEM pixel; the number of ASTER scenes used (up to 100), if ASTER; and the number of SRTM data takes (up to 24), if SRTM. The NUM file for both 3 arc second products (whether sampled or averaged) references the 3 x 3 center pixel. Note that NUMs less than 6 are water and those greater than 10 are land. The 3 arc second data was derived from the 1 arc second using sampling and averaging methods. (See Figure 3 in the User Guide (https://lpdaac.usgs.gov/documents/179/SRTM_User_Guide_V3.pdf).

The NASA SRTM data sets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA - previously known as the National Imagery and Mapping Agency, or NIMA), as well as the participation of the German and Italian space agencies. This collaboration aims to generate a near-global digital elevation model (DEM) of Earth using radar interferometry. SRTM was the primary (and virtually only) payload on the STS-99 mission of the Space Shuttle Endeavour, which launched February 11, 2000 and flew for 11 days.

The SRTM swaths extended from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km), creating swaths ~225 km wide, and consisted of all land between 60° N and 56° S latitude to account for 80% of Earth’s total landmass.

Improvements/Changes from Previous Versions * Voids in the Version 3.0 products have been filled with ASTER Global Digital Elevation Model (GDEM) Version 2.0, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010), and the National Elevation Dataset (NED).

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date November 12, 2020
Metadata Updated Date December 6, 2023

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date November 12, 2020
Metadata Updated Date December 6, 2023
Publisher LP DAAC
Maintainer
Identifier C204582037-LPDAAC_ECS
Data First Published 2013-09-04
Language en-US
Data Last Modified 2015-09-02
Category SRTM, geospatial
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://data.nasa.gov/data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Citation NASA JPL. 2013-11-20. SRTMGL3N.003. NASA Shuttle Radar Topography Mission Global 3 arc second number. Archived by National Aeronautics and Space Administration, U.S. Government, NASA EOSDIS Land Processes DAAC. https://doi.org/10.5067/MEASURES/SRTM/SRTMGL3N.003. https://doi.org/10.5067/MEaSUREs/SRTM/SRTMGL3N.003. The DOI landing page provides citations in APA and Chicago styles..
Creator NASA JPL
Harvest Object Id b655462a-094d-4656-abd1-e701c5a6580c
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://doi.org/10.5067/MEASURES/SRTM/SRTMGL3N.003
Metadata Type geospatial
Old Spatial -180.0 -56.0 180.0 60.0
Program Code 026:001
Series Name SRTMGL3N.003
Source Datajson Identifier True
Source Hash 7644c2780b62a9655c1abf158686afa256f79b57d8841752f2107ad57eae239b
Source Schema Version 1.1
Spatial
Temporal 2000-02-11T00:00:00Z/2000-02-21T23:59:59Z

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