SRTMSWBD v003

NASA Shuttle Radar Topography Mission Water Body Data Shapefiles and Raster Files


PI: Michael Kobrick, Robert Crippen

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) SRTM, which includes the Water Body Data Shapefiles and Raster Files (~30 m) product. Version 3.0 contains the vectorized coastline masks used by National Geospatial-Intelligence Agency (NGA) in the editing, called the SRTM Waterbody Data (SWBD), in shapefile and rasterized formats.

The NASA SRTM data sets result from a collaborative effort by the National Aeronautics and Space Administration (NASA) and the 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.

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Characteristics

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)

Collection and Granule

Collection

Characteristic Description
CollectionMEaSUREs SRTM
DOI10.5067/MEaSUREs/SRTM/SRTMSWBD.003
File Size~0.03 MB
Temporal ResolutionMulti-Day
Temporal Extent2000-02-11 to 2000-02-21
Spatial ExtentGlobal (60°N to 56°S, 180°W to 180°E)
Coordinate SystemGeographic Latitude and Longitude
DatumWGS84/EGM96
File FormatRAW
Geographic Dimensions1° x 1°

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers1
Columns/Rows3601 x 3601
Pixel Size~30 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
RAW Water Body Attribute Class 8-bit unsigned integer N/A N/A 0, 255 N/A

Water Body Attribute

Class Description
0 Land
255 Water

Product Quality

Scientists used a method called Kinematic Global Positioning System Geodetic field surveying to validate the SRTM data. This method facilitates the very rapid long lines of precise positions from a moving vehicle. Several entities conducted the actual survey work, including private contractors, NGA geodesists and NASA Jet Propulsion Laboratory (JPL) scientists. In all, about 70,000 kilometers of survey lines were collected in support of this mission. The data were used to model long-wavelength error sources.

In addition, NASA’s JPL deployed corner reflectors during the mission. These are highly reflective structures that appear as a bright point in the radar image. These reflectors deployed with precisely measured coordinates, served as control points in the Shuttle Radar Topography Mission data.

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

Documentation

Using the Data

Tools

Citation

DOI: 10.5067/MEaSUREs/SRTM/SRTMSWBD.003

About the Image

NASA Shuttle Radar Topography Mission Water Body Data Shapefiles and Raster Files water body attributes data from the SRTMSWBD product over the Democratic Republic of the Congo, 2000.

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