The Shuttle Radar Topography Mission is a collaborative project between NASA, the National Imagery and Mapping Agency (NIMA), and the German and Italian space agencies to map the elevation of a large part of the globe. SRTM consisted of a specially modified radar system that flew onboard the Space Shuttle Endeavour during an 11-day mission in February of 2000. The instrument operated virtually flawlessly and imaged 99.96% of the targeted landmass at least one time, 94.59% at least twice and about 50% at least three or more times. The goal was to image each terrain segment at least twice from different angles (on ascending, or north-going, and descending orbit passes) to fill in areas shadowed from the radar beam by terrain. The 'targeted landmass' consisted of all land between 56 degrees south and 60 degrees north latitude, which comprises almost exactly 80% of the total landmass.
While SRTM30 has the same resolution as GTOPO30, it can be considered a more accurate global digital data set compared to GTOPO30 because of its seamless and uniform representation, due to the fact that it was created over a short period of time from a single source rather than from the numerous sources spanning many decades that went into creating the GTOPO30 data set.
This data set does not provide the high resolution SRTM elevation of the original one degree datasets. Sample spacing for the original individual data points is either 1 arc-second or 3 arc-seconds, referred to as SRTM-1 and SRTM-3, respectively. The user may visit <ftp://e0mss21u.ecs.nasa.gov/srtm/> or <ftp://e0mss21u.ecs.nasa.gov/srtm/> to obtain the higher resolution datasets.
Paskevich, Valerie, 200508, srtm30plus-world_pctshade.tif - SRTM30PLUS color encoded shaded relief world topography (approximately 4km) GeoTIFF image: Open-File Report 2005-1001, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.This is part of the following larger work.Online Links:
- <http://pubs.usgs.gov/of/2005/1001/data/basemaps/srtm30plus/srtm30plus-world_pctshade.zip>
- <http://pubs.usgs.gov/of/2005/1001/htmldocs/datacatalog.htm>
Poppe, L.J., Williams, S.J., and Paskevich, V.F., 2005, U.S. Geological Survey East-Coast Sediment Analysis: Procedures, Database, and GIS Data: Open-File Report 2005-1001, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.Online Links:
This is a Raster data set. It contains the following raster data types:
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.033333. Longitudes are given to the nearest 0.033333. Latitude and longitude values are specified in Decimal degrees.
The horizontal datum used is D_WGS_1984.
The ellipsoid used is WGS_1984.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257224.
Please credit Joseph J. Becker, David T. Sandwell for the compilation of the Land and Ocean data used as the source.
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
This image provides a broad scale view of the world topography (elevation and bathymetry) on which other Geographic Information System (GIS) data layers may be co-located and viewed.These data are intended for science researchers, students, policy makers, and the general public. The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information.
Becker, Joseph J. , and Sandwell, David T. , 200412, SRTM30_PLUS: SRTM30, Coastal and Ridge Multibeam, Estimated Topography: Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA.Online Links:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
Data sources produced in this process:
Elevation Data - Each SRTM data tile contains a mosaic of elevations generated by averaging all data takes that fall within that tile. Since the primary error source in synthetic aperture radar data is speckle, which has the characteristics of random noise, combining data through averaging reduces the error by the square root of the number of data takes used. In the case of SRTM the number of data takes could range from a minimum of one (in a very few cases) up to as many as ten or more.
Land data are based on the 1-km averages of topography derived from the USGS SRTM30 grided DEM data product created with data from the NASA Shuttle Radar Topography Mission. GTOPO30 data are used for high latitudes where SRTM data are not available. Ocean data are based on the Smith and Sandwell global 2-minute grid between latitudes +/- 72 degrees. Higher resolution grids have been added from the LDEO Ridge Multibeam Synthesis Project and the NGDC Coastal Relief Model. Arctic bathymetry is from the International Bathymetric Chart of the Oceans (IBCAO) [Jakobsson et al., 2003].
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- Bathymetry is not to be used for navigational purposes.
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
All source data are derived from public domain sources and these data are also in the public domain.
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(508) 457-2310 (FAX)
Downloadable Data
Although this data set has been used by the U.S. Geological Survey (USGS), no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Trade, firm, or product names and other references to non-USGS products and services are provided for information only and do not constitute endorsement or warranty, express or implied, by the USGS, USDOI, or U.S. Government, as to their suitability, content, usefulness, functioning, completeness, or accuracy.
| Data format: | Archive containing GeoTIFF image, world file and metadata. in format TIFF GeoTIFF image Size: 0.000 |
|---|---|
| Network links: |
<http://pubs.usgs.gov/of/2005/1001/data/basemaps/srtm30plus/srtm30plus-world_pctshade.zip> |
| Media you can order: |
DVD-ROM
(Density 4.75
Gbytes)
(format UDF)
|
This image is available as a GEOTIFF image with an accompanying world file. To utilize this data, the user must have an image viewer, image processing or GIS software package capable of importing a GeoTIFF image.
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov
