For the United States, data was made available at 1-arc second resolution (approximately 30m at the equator), but for the rest of the world, the 1-arc second product is degraded to 3-arc seconds (approximately 90m at the equator). The data was released continent by continent, as and when the data was processed by NASA and the USGS.
The first release of Shuttle Radar Topography Mission (SRTM) data was provided in 1-degree digital elevation model (DEM) tiles from the USGS FTP server ( ) in 2003. In addition, a binary Data Mask file is available for download, allowing users to identify the areas within each DEM which has been interpolated.
#Elevation one in a million zip software#
These files are available for download in both Arc-Info ASCII format, and as GeoTiff, for easy use in most GIS and Remote Sensing software applications. The DEM files have been mosaiced into a seamless near-global coverage (up to 60 degrees north and south), and are available for download as 5-degree x 5-degree tiles, in a geographic coordinate system – WGS84 datum. These processes were implemented using Arc/Info and an AML script. These interpolated DEM values are then used to fill in the original no-data holes within the SRTM data. This involved the production of vector contours and points and the re-interpolation of these derived contours back into a raster DEM. These are generally small holes, which nevertheless render the data less useful, especially in fields of hydrological modeling.Īndy Jarvis and Edward Guevara of the CIAT Agroecosystems Resilience project, Hannes Isaak Reuter (JRC-IES-LMNH) and Andy Nelson (JRC-IES-GEM) have further processed the original DEMs to fill in these no-data voids. The data currently being distributed by NASA/USGS (finished product) contains “no-data” holes where water or heavy shadow prevented the quantification of elevation. The vertical error of the DEM’s is reported to be less than 16m. A 1 arc second data product was also produced but is not available for all countries. The SRTM data is available as 3 arc second (approx.
#Elevation one in a million zip free#
This data is currently distributed free of charge by USGS and is available for download from the National Map Seamless Data Distribution System, or the USGS FTP site. If you find this digital elevation data useful, please let us know at NASA Shuttle Radar Topographic Mission (SRTM) has provided digital elevation data (DEMs) for over 80% of the globe. Data can be downloaded using a browser or accessed directly from the FTP site. These are available in both ArcInfo ASCII and GeoTiff format to facilitate their ease of use in a variety of image processing and GIS applications.
All are produced from a seamless dataset to allow easy mosaicing. The SRTM 90m DEM’s have a resolution of 90m at the equator, and are provided in mosaiced 5 deg x 5 deg tiles for easy download and use. Digital elevation models (DEM) for the entire globe, covering all of the countries of the world, are available for download on this site. This data is provided in an effort to promote the use of geospatial science and applications for sustainable development and resource conservation in the developing world. The SRTM digital elevation data provided on this site has been processed to fill data voids and to facilitate its ease of use by a wide group of potential users. A sample elevation map of Central Africa at 90m spatial resolution (Tile 42_12) Download
0 kommentar(er)
