Raw radar images used to map Earth's terrain (SRTM)
What it measures. Raw radar image files holding brightness values from a shuttle radar, plus quality files about the viewing angle, at about 30 m resolution. Every image pixel the radar collected is included, even partial coverage.
How it's made. Captured during the Space Shuttle Endeavour's 11-day SRTM mission in 2000, which carried radar to image Earth's terrain; this is the earliest, unprocessed swath imagery from that flight.
How & where you'd use it. A raw building-block input used to create near-global elevation maps; most people use the finished elevation models rather than these raw radar images directly.
What's measured
Coverage & cadence
- Time span2000-02-11 → 2000-02-21
- Measured bySTS-99 (SRTM)
- Processing levelLevel 3
- Spatial extent-180, -56, 180, 60
- FormatsBinary
- 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 NASA Making Earth System Data Records for Use in Research Environments ([MEaSUREs](https://earthdata.nasa.gov/about/competitive-programs/measures )) SRTM, which includes the global 1 arc second (~30 meter) swath (raw) image data product. (See User Guide Section 2.2.1) The SRTM swath image data set consists of radar image files containing brightness values, as well as quality assurance (incidence angle) files for each of four overlapping sub-swaths that passes through a 1 degree by 1 degree tile. Data from each sub-swath is included as a separate file. Some files may contain only partial data; however, every image pixel acquired by SRTM is included in this data set. 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. 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
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="SRTMIMGR",
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. Official links
- Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. GET DATA
- The technical information in the User's Guide enables users to interpret and use the data products. VIEW RELATED INFORMATION
- The SRTM Quick Guide provides an overview of available products. VIEW RELATED INFORMATION
- The ATBD provides physical theory and mathematical procedures for the calculations used to produce the data products. VIEW RELATED INFORMATION