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Full catalog/SRTMGL1_NC
SRTMGL1_NC·v003·dataset

Elevation map of Earth's land (SRTM radar, 30 m)

NASA Shuttle Radar Topography Mission Global 1 arc second NetCDF V003
land NASA LPCLOUD Level 3 netCDF-4
In plain English

What it measures. An elevation map of Earth's land surface at about 30-meter spacing, giving the height of the ground across roughly 80% of the planet's landmass (between 60 N and 56 S).

How it's made. Made from radar measurements taken by the Space Shuttle Endeavour during its 11-day SRTM mission in 2000, then processed into blended elevation tiles.

How & where you'd use it. A foundational map widely used for mapping, flood and terrain analysis, planning, and as a base layer in countless other Earth-science products.

What's measured

SPECTRAL/ENGINEERING › RADAR › RADAR IMAGERYLAND SURFACE › TOPOGRAPHY › TERRAIN ELEVATIONLAND SURFACE › TOPOGRAPHY › TERRAIN ELEVATION › TOPOGRAPHICAL RELIEF MAPS

Coverage & cadence

  • Time span2000-02-11 → 2000-02-21
  • Measured bySTS-99 (SRTM C-BAND RADAR)
  • Processing levelLevel 3
  • Spatial extent-180, -56, 180, 60
  • FormatsnetCDF-4
  • StatusCOMPLETE

What you can do with it

  • Track deforestation, fire scars and land-cover change
  • Monitor crop and vegetation health (NDVI/EVI)
  • Map how built-up vs. green an area is over time
Official 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](https://earthdata.nasa.gov/about/competitive-programs/measures )) version SRTM, which includes the global 1 arc second (~30 meter) product. NASA Shuttle Radar Topography Mission (SRTM) datasets 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. The purpose of SRTM was to generate a near-global digital elevation model (DEM) of the Earth using radar interferometry. SRTM was a primary component of the payload on the Space Shuttle Endeavour during its STS-99 mission. Endeavour launched February 11, 2000 and flew for 11 days. SRTM collected data in swaths, which extend from ~30 degrees off-nadir to ~58 degrees off-nadir from an altitude of 233 kilometers (km). These swaths are ~225 km wide, and consisted of all land between 60° N and 56° S latitude. This accounts for about 80% of Earth's total landmass. Each SRTMGL1 data tile contains a mosaic and blending of elevations generated by averaging all "data takes" that fall within that tile. These elevation files use the extension ".HGT", meaning height (such as N37W105.SRTMGL1.HGT). The primary goal of creating the Version 3 data was to eliminate voids that were present in earlier versions of SRTM data. In areas with limited data, existing topographical data were used to supplement the SRTM data to fill the voids. The source of each elevation pixel is identified in the corresponding [SRTMGL1N](https://doi.org/10.5067/MEaSUREs/SRTM/SRTMGL1N.003) product (such as N37W105.SRTMGL1N.NUM). The global 1 arc second SRTM product is also available in NetCDF4 format as the SRTMGL1_NC dataset with the source of each elevation pixel in the corresponding SRTMGL1_NUMNC product. Known Issues * Known issues in the NASA SRTM are described in the following publication: * Rodriguez, E., C. S. Morris, and J. E. Belz (2006), A global assessment of the SRTM performance, Photogramm. Eng. Remote Sens., 72, 249–260. https://doi.org/10.14358/PERS.72.3.249

Get the data

srtmgl1_nc_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="SRTMGL1_NC",
    version="003",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from LPCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.