Culminating more than four years of processing data, NASA and the National Geospatial-Intelligence Agency (NGA) have completed Earth's most extensive global topographic map. The mission is a collaboration among NASA, NGA, and the German and Italian space agencies. For 11 days in February 2000, the space shuttle Endeavour conducted the Shuttle Radar Topography Mission (SRTM) using C-Band and X-Band interferometric synthetic aperture radars to acquire topographic data over 80% of the Earth's land mass, creating the first-ever near-global data set of land elevations. This data was used to produce topographic maps (digital elevation maps) 30 times as precise as the best global maps used today. The SRTM system gathered data at the rate of 40,000 per minute over land. They reveal for the first time large, detailed swaths of Earth's topography previously obscured by persistent cloudiness. The data will benefit scientists, engineers, government agencies and the public with an ever-growing array of uses. The SRTM radar system mapped Earth from 56 degrees south to 60 degrees north of the equator. The resolution of the publicly available data is three arc-seconds (1/1,200th of a degree of latitude and longitude, about 295 feet, at Earth's equator). The final data release covers Australia and New Zealand in unprecedented uniform detail. It also covers more than 1,000 islands comprising much of Polynesia and Melanesia in the South Pacific, as well as islands in the South Indian and Atlantic oceans. SRTM data are being used for applications ranging from land use planning to "virtual" Earth exploration. Currently, the mission's homepage "http://www.jpl.nasa.gov/srtm" provides direct access to recently obtained earth images. The Shuttle Radar Topography Mission C-band data for North America and South America are available to the public. A list of complete public data set is available at "http://www2.jpl.nasa.gov/srtm/dataprod.htm" The data specifications are within the following parameters: 30-meter X 30-meter spatial sampling with 16 meter absolute vertical height accuracy, 10-meter relative vertical height accuracy, and 20-meter absolute horizontal circular accuracy. From the JPL Mission Products Summary, "http://www.jpl.nasa.gov/srtm/dataprelimdescriptions.html". The primary products of the SRTM mission are the digital elevation maps of most of the Earth's surface. Visualized images of these maps are available for viewing online. Below you will find descriptions of the types of images that are being generated: Radar Image Radar Image with Color as Height Radar Image with Color Wrapped Fringes -Shaded Relief Perspective View with B/W Radar Image Overlaid Perspective View with Radar Image Overlaid, Color as Height Perspective View of Shaded Relief Perspective View with Landsat or other Image Overlaid Contour Map - B/W with Contour Lines Stereo Pair Anaglypgh The SRTM radar contained two types of antenna panels, C-band and X-band. The near-global topographic maps of Earth called Digital Elevation Models (DEMs) are made from the C-band radar data. These data were processed at the Jet Propulsion Laboratory and are being distributed through the United States Geological Survey's EROS Data Center. Data from the X-band radar are used to create slightly higher resolution DEMs but without the global coverage of the C-band radar. The SRTM X-band radar data are being processed and distributed by the German Aerospace Center, DLR.

The Shuttle Radar Topography Mission (SRTM) was flown aboard the space shuttle Endeavour February 11-22, 2000. The National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA) participated in an international project to acquire radar data which were used to create the first near-global set of land elevations. The radars used during the SRTM mission were actually developed and flown on two Endeavour missions in 1994. The C-band Spaceborne Imaging Radar and the X-Band Synthetic Aperture Radar (X-SAR) hardware were used on board the space shuttle in April and October 1994 to gather data about Earth's environment. The technology was modified for the SRTM mission to collect interferometric radar, which compared two radar images or signals taken at slightly different angles. This mission used single-pass interferometry, which acquired two signals at the same time by using two different radar antennas. An antenna located on board the space shuttle collected one data set and the other data set was collected by an antenna located at the end of a 60-meter mast that extended from the shuttle. Differences between the two signals allowed for the calculation of surface elevation. Endeavour orbited Earth 16 times each day during the 11-day mission, completing 176 orbits. SRTM successfully collected radar data over 80% of the Earth's land surface between 60° north and 56° south latitude with data points posted every 1 arc-second (approximately 30 meters). Two resolutions of finished grade SRTM data are available through EarthExplorer from the collection held in the USGS EROS archive: 1 arc-second (approximately 30-meter) high resolution elevation data offer worldwide coverage of void filled data at a resolution of 1 arc-second (30 meters) and provide open distribution of this high-resolution global data set. Some tiles may still contain voids. The SRTM 1 Arc-Second Global (30 meters) data set will be released in phases starting September 24, 2014. Users should check the coverage map in EarthExplorer to verify if their area of interest is available. 3 arc-second (approximately 90-meter) medium resolution elevation data are available for global coverage. The 3 arc-second data were resampled using cubic convolution interpolation for regions between 60° north and 56° south latitude. [Summary provided by the USGS.]

The CGIAR-CSI GeoPortal is able to provide SRTM 90m Digital Elevation Data for the entire world. The SRTM digital elevation data, produced by NASA originally, is a major breakthrough in digital mapping of the world, and provides a major advance in the accessibility of high quality elevation data for large portions of the tropics and other areas of the developing world. The SRTM digital elevation data provided on this site has been processed to fill data voids, and to facilitate it's ease of use by a wide group of potential users. 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. Digital elevation models (DEM) for the entire globe, covering all of the countries of the world, are available for download on this site. 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. All are produced from a seamless dataset to allow easy mosaicing. 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. Data can be downloaded using a browser or accessed directly from the ftp site.

Computed Digital Terrain Model (DTM) from SRTM data on the basis of OpenStreetMap data (timestamp 3/2011)

The Shuttle Radar Topography Mission (SRTM, see Farr et al. 2007) digital elevation data is an international research effort that obtained digital elevation models on a near-global scale. This SRTM V3 product (SRTM Plus) is provided by NASA JPL at a resolution of 1 arc-second (approximately 30m). This dataset has undergone a void-filling process using open-source data (ASTER GDEM2, GMTED2010, and NED), as opposed to other versions that contain voids or have been void-filled with commercial sources. For more information on the different versions see the SRTM Quick Guide. Documentation: User's Guide General Documentation Algorithm Theoretical Basis Document (ATBD)

Void filled SRTM Digital Surface Model (DSM) and computed Digital Terrain Model (DTM) on the basis of OpenStreetMap data.

A global 1-km resolution land surface digital elevation model (DEM) derived from U.S. Geological Survey (USGS) 30 arc-second SRTM30 gridded DEM data created from the NASA Shuttle Radar Topography Mission (SRTM). GTOPO30 data are used for high latitudes where SRTM data are not available. For a grayscale hillshade image layer of this dataset, see "world_srtm30plus_dem1km_hillshade" in the distribution links listed in the metadata.

The Shuttle Radar Topography Mission (SRTM) obtained elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth. SRTM consisted of a specially modified radar system that flew onboard the Space Shuttle Endeavour during an 11-day mission in February of 2000. SRTM is an international project spearheaded by the National Geospatial-Intelligence Agency (NGA) and the National Aeronautics and Space Administration (NASA).

Version 3: Elimination of the voids in the NASA SRTM DEM was the primary goal of a project under the NASA MEaSUREs (Making Earth System Data Records for Use in Research Environments) Program. Ultimately this was achieved by filling the voids with elevation data primarily from the ASTER GDEM2 (Global Digital Elevation Model Version 2) and secondarily from the USGS GMTED2010 elevation model or the USGS National Elevation Dataset (NED). For more information on this dataset visit the LP DAAC NASA Shuttle Radar Topography Mission Global 3 arc second page.

The Shuttle Radar Topography Mission (SRTM) digital elevation dataset was originally produced to provide consistent, high-quality elevation data at near global scope. This version of the SRTM digital elevation data has been processed to fill data voids, and to facilitate its ease of use.

NASA has released version 2 of the Shuttle Radar Topography Mission digital topographic data (also known as the "finished" version). Version 2 is the result of a substantial editing effort by the National Geospatial Intelligence Agency and exhibits well-defined water bodies and coastlines and the absence of spikes and wells (single pixel errors), although some areas of missing data ('voids') are still present. The Version 2 directory also contains the vector coastline mask derived by NGA during the editing, called the SRTM Water Body Data (SWBD), in ESRI Shapefile format.

                [Summary provided by NASA.]

SRTM data are also available globally at 1 arc second resolution (SRTMGL1.003) through the Data Pool (https://e4ftl01.cr.usgs.gov/MEASURES/SRTMGL1.003/) or from EarthExplorer where it is listed as NASA SRTM3 SRTMGL1. Please sign in with NASA Earthdata Login Credentials to download data from the NASA LP DAAC Collections. These datasets require login on both NASA Earthdata and USGS EarthExplorer systems to access data. After you create your account, you will also need to “authorize” the LP DAAC Data Pool application. On the Profile page in your Earthdata account you will need to select My Applications. On that page make sure the LP DAAC Data Pool is listed. If it isn't then select Authorize More Applications. In the dialog box type in LP DAAC Data Pool and click Search For Applications. Select Approve when presented with the lpdaac_datapool. Keep everything checked but you can uncheck the Yes, I would like to be notified box. Select Authorize and the LP DAAC Data Pool should be added to your Approved Applications. You might benefit from using the AppEEARS tool. · o AppEEARS landing page: https://lpdaacsvc.cr.usgs.gov/appeears/ · o The users will need and https://urs.earthdata.nasa.gov/?_ga=2.148606453.334533939.1615325167-1213876668.1613754504. Click or tap if you trust this link.">Earthdata Login · o Getting started instructions can be found here: https://lpdaacsvc.cr.usgs.gov/appeears/help Previously available here: Digital Elevation Model of Ireland, from NASA's Shuttle Radar Topography Mission (SRTM), sampled at 3 arc second intervals in latitude & longitude (about every 90m) in heightmap (.HGT) format.''Latitudes & longitudes are referenced to WGS84, heights are in meters referenced to the WGS84/EGM96 geoid.'' Please see the linked pdf files for further documentation.''A QGIS project for the hgt files is also attached.

Data represents the Shuttle Radar Topography Mission (SRTM) 30 metres image for Kenya.These SRTM was created through mosaicking tiles and clippingto the extent of the country

Radar data at 250m. All tiles required for a representation of Europe.Property of NASA, downloaded from https://srtm.csi.cgiar.org.Re-projected at the Berlin University of Applied Sciences according to EPSG 102014 (in metres, centred on 10° East).We also offer the data as a tiled imagery layer. Radar-Daten in 250m. Alle Kacheln, die für eine Darstellung von Europa benötigt werden.Eigentum der NASA, runtergeladen von https://srtm.csi.cgiar.org.An der Berliner Hochschule für Technik umprojiziert nach EPSG 102014 (in Meter, zentriert auf 10° Ost).Weiterhin bieten wir die Daten als tiled imagery layer an.

The Shuttle Radar Topography Mission (SRTM) successfully collected Interferometric Synthetic Aperture Radar (IFSAR) data over 80 percent of the landmass of the Earth between 60 degrees North and 56 degrees South latitudes in February 2000. The mission was co-sponsored by the National Aeronautics and Space Administration (NASA) and National Geospatial-Intelligence Agency (NGA). NASA's Jet Propulsion Laboratory (JPL) performed preliminary processing of SRTM data and forwarded partially finished data directly to NGA for finishing by NGA's contractors and subsequent monthly deliveries to the NGA Digital Products Data Wharehouse (DPDW). All the data products delivered by the contractors conform to the NGA SRTM products and the NGA Digital Terrain Elevation Data (DTED) to the Earth Resources Observation & Science (EROS) Center. The DPDW ingests the SRTM data products, checks them for formatting errors, loads the SRTM DTED into the NGA data distribution system, and ships the public domain SRTM DTED to the U.S. Geological Survey (USGS) Earth Resources Observation & Science (EROS) Center. Two resolutions of finished grade SRTM data are available through EarthExplorer from the collection held in the USGS EROS archive: 1 arc-second (approximately 30-meter) high resolution elevation data are only available for the United States. 3 arc-second (approximately 90-meter) medium resolution elevation data are available for global coverage. The 3 arc-second data were resampled using cubic convolution interpolation for regions between 60° north and 56° south latitude. [Summary provided by the USGS.]

The Shuttle Radar Topography Mission (SRTM, DTS-99) from February 11 to 22, 2000 was an US-German-Italian effort to produce a first global digital elevation model (DEM). The German Aerospace Center (DLR) and the Italian Space Agency (ASI) complemented the US C-band Synthetic Aperture Radar (SAR) payload of NASA/JPL with an additional X-SAR instrument. The SRTM X-SAR DEM was generated at DLR from this instrument’s data using radar interferometry technique. The data was acquired simultaneously from aboard the Space Shuttle Endeavor employing two SAR antennas, one inside the Space Shuttle’s cargo bay, the other at the end of a 60 m extension pole. A substantial portion of the global land surface between 60° northern and 58° southern latitude was covered. As the orbit flown and imaging period of the SRTM mission had been optimised for the US C-band system, the German-Italian X-SAR with narrower aperture angle imaged data only along roughly 50 km wide orbital ground traces. So, the dataset available shows a grid-like coverage. The original SRTM X-SAR DTED DEMs have been merged to 10° by 10° tiles, converted to GeoTIFF format and packaged into zip-archives. Each zip-file contains the DEM dataset, the corresponding height error map (HEM), a quicklook png-image, a kml-overlay and a readme document. The filename of the zip-archive specifies the bottom left coordinate of each tile. The zip-archives can be downloaded via the EOC Download Service.

For more information see: https://geoservice.dlr.de/resources/licenses/srtm_xsar/DLR_SRTM_XSAR_ReadMe.pdf

The 3 second (~90m) Shuttle Radar Topographic Mission (SRTM) Digital Elevation Model (DEM) version 1.0 was derived from resampling the 1 arc second (~30m) gridded DEM (ANZCW0703013355). The DEM represents ground surface topography, and excludes vegetation features. The dataset was derived from the 1 second Digital Surface Model (DSM; ANZCW0703013336) by automatically removing vegetation offsets identified using several vegetation maps and directly from the DSM. The 1 second product provides substantial improvements in the quality and consistency of the data relative to the original SRTM data, but is not free from artefacts. Man-made structures such as urban areas and power line towers have not been treated. The removal of vegetation effects has produced satisfactory results over most of the continent and areas with defects are identified in the quality assessment layers distributed with the data and described in the User Guide (Geoscience Australia and CSIRO Land & Water, 2010). A full description of the methods is in progress (Read et al., in prep; Gallant et al., in prep). The 3 second DEM was produced for use by government and the public under Creative Commons attribution.

The Shuttle Radar Topography Mission (SRTM) was a partnership between NASA and the National Geospatial-Intelligence Agency (NGA). Flown aboard the NASA Space Shuttle Endeavour (11-22 February 2000), SRTM fulfilled its mission to map the world in three dimensions. The USGS is under agreement with NGA and NASA's Jet Propulsion Laboratory to distribute SRTM elevation products derived from the C-band radar data. SRTM utilized interferometric C-band Spaceborne Imaging Radar to generate elevation data over 80 percent of the Earth's land surface. Global SRTM data at a resolution of 1 arc-second have been edited to delineate and flatten water bodies, better define coastlines, remove spikes and wells, and fill small voids. Larger areas of missing data or voids were filled by the NGA using interpolation algorithms in conjunction with other sources of elevation data. The SRTM 1 Arc-Second Global data offer worldwide coverage of void filled data at a resolution of 1 arc-second (30 meters) and provide open distribution of this high-resolution global data set.

The Shuttle Radar Topography Mission data at 30meters resolution for Tanzania. Referenced tiles were mosaicked and clipped to the extent of the country.

Radar data at 250m. All tiles required for a representation of Europe.Property of NASA, downloaded from https://srtm.csi.cgiar.org.Re-projected at the Berlin University of Applied Sciences according to EPSG 102014 (in metres, centred on 10° East).We also offer the download as a zipped GeoTiff. Radar-Daten in 250m. Alle Kacheln, die für eine Darstellung von Europa benötigt werden.Eigentum der NASA, runtergeladen von https://srtm.csi.cgiar.org.An der Berliner Hochschule für Technik umprojiziert nach EPSG 102014 (in Meter, zentriert auf 10° Ost).Weiterhin bieten wir den Download als gezipptes GeoTiff an.

MERIT (Multi-Error-Removed Improved Terrain DEM) is a substantially improved near-global terrain description with 90 m (3 arc-seconds) spatial resolution (Yamazaki et al. 2017). MERIT covers almost all of Earth’s land areas within 90N-60S, except of Antarctica. Different to most other global DEM data sets, MERIT provides – in good approximation – elevations of the bare ground. This has been achieved by reducing vegetation heights (known as tree height bias) using tree density and tree height maps as auxiliary information in the production of the MERIT DEM. However, over built areas, MERIT elevations may contain a bias due to urban canopy.MERIT relies on SRTM v2.1 South of 60° latitude, ALOS AW3D North of 60° latitude, and uses elevations from Viewfinder Panoramas (VFP-DEM) to fill voids (unobserved areas) where present. For the void-filling with VFP-DEM, an average matching method has been applied by Yamazaki et al. (2017) to ensure smooth transitions. Within the SRTM data area, about 0.5 % of MERIT land cells rely on VFP-DEM. North of 60°, the contribution of VFP-DEM is about ~30 %. As a result, elevation errors previously present in the SRTM model have been reduced such that actual terrain features stand out more clearly.

Geodetic information: The MERIT DEMs are vertically referenced to the EGM96 geoid and horizontally referenced to the WGS84 (World Geodetic System 1984).

Further notes: The MERIT DEM mostly represents bare ground elevations, so is technically close to a digital terrain model (DTM). This makes the data set suitable for applications requiring heights of the bare ground. Example areas are hydrology, hydrodynamics, physical geodesy and geophysics.

Data access: The authors freely share their model for non-commercial applications (e.g. science and education) via URL: hydro.iis.u-tokyo.ac.jp/~yamadai/MERIT_DEM/

References:

Yamazaki, D., D. Ikeshima, R. Tawatari, T. Yamaguchi, F. O’Loughlin, J.C. Neal, C.C. Sampson, S. Kanae, P.D. Bates (2017), A high accuracy map of global terrain elevations, Geophysical Research Letters, Doi: 10.1002/2017GL072874