The overall purpose of this paper is to perform an accuracy assessment of the free to download dems. Pdf comparative analysis of aster dem, aster gdem, and srtm. Nasa worldview visually explore the past and the present of this dynamic planet from a satellites perspective. Dems have also been called dtm digital terrain models, with buildings and vegetation excluded and dsms digital surface models, including vegetation and buildings. A digital elevation model dem is a raster data set with a regular grid of elevations arranged by column and row. Pdf assessment of classical, aster and srtm dems in nairobi. The gdem was created by processing and stereocorrelating the 1. Aster global digital elevation model aster gdem easytouse topographic information of the global terrain the ministry of economy, trade and industry of japan meti and the national aeronautics and space administration nasa are collaborating on a project to develop aster global digital elevation model aster gdem, a dem data which is acquired by a satelliteborne sensor aster to. This shows the relative relationships of the different dems. Haeberli and hoelzle, 1995 is a globally complete glacier inventory e. Gmted2010 or global multiresolution terrain elevation data 2010, is a replacement for the gtopo30 dem, created by the u. Download, chrome list, and then pick the text file with the list of aster tiles. A closer look at figure 3 reveals that there is a sharp difference at stations 42, 1 and 40 for alos w3d30, srtm30 and aster gdem2 respectively.
The aster advanced spaceborne thermal emission and reflection radiometer instrument was built by meti and launched onboard. Nasa has released version 2 of the shuttle radar topography mission digital topographic data also known as the finished version. The ministry of economy, trade, and industry meti of japan and the united states national aeronautics and space administration nasa jointly announced the release of the advanced spaceborne thermal emission and reflection radiometer aster global digital elevation model version 3 gdem 003, and the aster water body dataset astwbd on. The first version of the aster gdem, released in june 2009, was generated. Aster gdem global digital elevation model has been produced as a joint activity of the ministry of economy, trade, and industry meti of japan and the united states national aeronautics and space administration nasa. Aster gdem and free aster l1al1b data see the nasa wist website. Comparison between srtm and aster derived dems allowed a qualitative assessment of the horizontal and vertical component of the error, while statistical measures were used to estimate their vertical accuracy. How to download aster global dem version 3 from earthdata. Download aster global dem data from earth explorer youtube. November 5, 2019 the aster global digital elevation model gdem version 3 astgtm provides a global digital elevation model dem of land areas on earth at a spatial resolution of 1 arc second approximately 30 meter horizontal posting at the equator.
Aster global dem version 3, and new aster water body dataset. You can view the latest information about these data at the usgs lp daac. Free digital elevation model dem and free satellite data. The ministry of economy, trade, and industry meti of japan and the united states national aeronautics and space administration nasa jointly announced the release of the advanced spaceborne thermal emission and reflection radiometer aster global digital elevation model version 3 gdem 003, and the aster. This is the final validated version of the dem product derived using bands 3n and 3b from an aster level1a data set. To upgrade your browser, click on the icons below to go to the download page. Free aster l1al1b data, source of stereo pairs for aster dems and a rich multi spectral dataset. This version 1 aster gdem gdem1 was compiled from over 1. Pdf comparative analysis of aster dem, aster gdem, and. This version of the ned was tested by comparison with the global. It coverage spans from 83 degrees north latitude to 83 degrees south, covering 99 per cent of earths landmass.
All cloudscreened dems are stacked and residual bad values and outliers are removed. Aster global digital elevation model gdem created from stereo pairs collected by the medium resolution satellite, aster, the gdem offers 30meter coverage between 83 north and 83 south. Download aster global dem data from earth explorer duration. The data are available with transformation services via the application for extracting and exploring analysis ready samples aeears. Elevation data provides height above the sea level in meters for every single place in the world, measured for regions of approximately 30x30 meters. The methodology used by japans sensor information laboratory corporation silc to produce the aster gdem involves automated processing of the entire aster level1a archive. Aster gdem and astwbd tiles may be downloaded from japan space systems and from the lp daac by visiting nasas earthdata search or downloading directly from the lp daacs data pool. We will incorporate glas data to remove artifacts at the optimal step in the srtm processing chain. The aster gdem is in geotif format with geographic latlong coordinates and a 1 arcsecond 30 m grid of elevation postings. You may zoom in, create polygon features, or enter pathrow information to select your area of interest. Query and order satellite images, aerial photographs, and cartographic products through the u.
Comparison of dems derived from usgs dlg, srtm, a statewide photogrammetry program, aster gdem and lidar. In order to use earthdata search, you must upgrade your web browser. Aster gdem global digital elevation model v002 select search for granules now begins the tedious part where there are over 22,000 aster gdem tiles that cover the globe however, the website only list 400 per page where there is an add all on page button but no add all option i. The aster global digital elevation model aster gdem version 3 v3 was generated using 1,880,306 level1a scenes acquired between march 1, 2000 and november 30, 20. The aster gdem covers land surfaces between 83n and 83s and is comprised of 22,702 tiles. The aster global digital elevation model version 2 gdem v2 is also a free dem that covers land surfaces between 83 deg. Using the dems of srtm with coverage from 56us to 60un and aster gdem with coverage from 83us to 83un, the elevation information is available to users free of charge almost worldwide. A new global aster dem gdem became available in 2009. One of the most required datasets for an improved calculation of current and future global sealevel rise e. Select from an array of stories below to learn more about worldview, the satellite imagery we provide and events occurring around the world. Earth, moon, or asteroid created from a terrains elevation data. The original version of the gdem featured at least 20m le90 vertical accuracy which was improved with the release of the second version. Pdf assessment of classical, aster and srtm dems in.
The methodology used to produce the aster gdem involved automated processing of the entire 1. These aster data are now available at the usgs earth explorer site. However, prior to their decision to release the aster gdem, nasa and meti, in cooperation with the u. The gdem s preproduction accuracy estimates were 20 meters at 95% confidence for vertical data, and 30 meters at 95% confidence for horizontal data. We use it as a generic term, and there are other more specific terms. The san francisquito creek project covers six usgs 7. Aster level4z is provided for a given square of approximately 60 x 60 km corresponding to the scene acquired by aster. Then select digital elevation, then aster global dem, and click results. Aster global dem version 3, and new aster water body.
The usgs spectral library is a reference data base containing reflectance spectra, and associated sample documentation, that can be used to identify minerals, determine mineral chemistry, discriminate between vegetation species, and detect hydrocarbons and contaminants in the environment. Aster digital elevation model ast14demrelative may 24, 2006 the current aster digital elevation model dem product was implemented using new production software at the land processes daac starting on may 24, 2006. After a short delay, the two image provide overlapping stereo imagery that allows creation of a photogrammetric dem. Srtm and aster for the area of najran city, saudi arabia. The aster gdem is a very large product, covering the vast reaches of the global land surface. The aster gdem is distributed as geographic tagged image file format geotiff files. The gdem and astwbd are available for download from nasa earthdata and.
The data which is in geographic decimal coordinates latitude and longitude is posted on one arcsecond. Aster global digital elevation model version 2 usgs. The usgs earth explorer gives a quick and intuitive way to download free aerial and satellite imagery. We will merge the improved srtm strip dems, refined aster and gdem v2 dems, and glas data using the srtm mosaic software to create a.
A second visual technique superimposes topographic profiles from each of the dems figure 5. Aster gdem was created by stacking all individual cloudmasked scene dems and noncloudmasked scene dems, then applying various algorithms to remove abnormal data 1, 2, 3. This tutorial is a demonstration of how to download a digital elevation model dem from the advanced spaceborne thermal emission and reflection radiometer aster version 2. We will merge the improved srtm strip dems, refined aster and gdem v2 dems, and glas data using the srtm mosaic software to create a seamless, voidfilled nasadem. Accuracy assessment of alos w3d30, aster gdem and srtm30.
Aug 16, 2019 aster gdem or advanced spaceborne thermal emission and reflection radiometer global digital elevation model, was created by nasa jpl and japans meti, and is now on version 3, offering improvements over previous versions of this dem. G dem will be the best freely available global digital elevation model dem at. Download aster dem digital elevation model for free from usgs how to download dem data from usgs download free dem digital elevation model download how to download dem digital elevation model usgs. On the suitability of the srtm dem and aster gdem for the. Nov 06, 2016 download aster dem digital elevation model for free from usgs how to download dem data from usgs download free dem digital elevation model download how to download dem digital elevation model usgs. Under the data sets tab, select digital elevation aster. A digital elevation model dem is a 3d cg representation of a terrains surface commonly of a planet e. Feb 18, 2020 we will incorporate glas data to remove artifacts at the optimal step in the srtm processing chain. Aster water body dataset astwbd, contains information on global water bodies. In contrast, aster gdem is developed based on a grid of 1 x 1 degree in latitude and longitude and requires no scene selection or mosaicking. Download aster dem digital elevation model for free from usgs.
A global dem refers to a discrete global grid dems are used often in geographic information systems, and are the most common basis for digitally produced relief maps. The aster global digital elevation model gdem version 3 astgtm provides a global digital elevation model dem of land areas on earth at a spatial resolution of 1 arc second approximately 30 meter horizontal posting at the equator. Elevation difference between srtm and aster products was evaluated using the root. Comparison of dems derived from usgs dlg, srtm, a statewide.
Comparison between srtm and asterderived dems allowed a qualitative assessment of the horizontal and vertical component of the error, while statistical measures were used to estimate their vertical accuracy. If you are going to performing analysis on the landsat data, the level 1 geotiff data product is probably the one youre after, which will be the largest file size. Selected data are averaged to create final pixel values, and residual anomalies are corrected before partitioning the data into 1 degree x 1 tiles. These six quads have been mosaicked together for your convenience of viewing and analyzing the information throughout the area. On june 29, 2009, nasa and the ministry of economy, trade and industry meti of japan released a global digital elevation model gdem to users worldwide at no charge as a contribution to the global earth observing system of systems geoss. The gdem is produced with 30meter 98feet postings, and is formatted as 23,000 onebyone degree tiles.
Its full validation and characterization will be achieved only after detailed study by the global user community. The aster scene was acquired november 20, 2001, and is centered near 28. In addition, how to merge two dem rasters and how to change the style of them in qgis 2. The original raw open data from us geological survey srtm 1arc, nasa and meti aster gdem and european union eudem has been modified. Nasa and meti release aster global dem version 3 usgs. Aster global dem aster is capable of collecting intrack stereo using nadir and aftlooking near infrared cameras. To learn more about dems, check out the dem page at the crater lake data clearinghouse web site. The aster gdem is available at no charge to users worldwide via electronic download from japan space systems and from nasas land.
In 2016, the usjapan aster advanced spaceborne thermal emission and reflection radiometer project. You can download the aster dem data for free from the usgs earth explorer. Aster global digital elevation model v003 metadata updated. Stereocorrelation is used to produce over one million individual scenebased aster dems, to which cloud masking is applied to remove cloudy pixels. The aster gdem was created with two nir cameras on the aster satellite. The usgs spectral library is a reference data base containing reflectance spectra. The original raw open data from us geological survey srtm 1arc, nasa and meti aster gdem and european union eudem has been modified, adapted and overlaid to fill the gaps and provide a. A new global elevation dataset known as g dem, based on the aster satellite imagery, will be released in late 2008. This dem is largely based on srtm data, with other sources filling in the gaps for worldwide coverage gmted2010 is available at three spatial resolutions, with the 7. In this video, i have clearly shown the steps required to download aster gdem v3 from earthdata. Srtm dem data is being housed on the usgs earth explorer. This view looking towards the northwest was created by draping an aster simulated natural color image over digital topography from the aster global digital elevation model gdem data set. The differences errors obtained in the heights between each of the dems and the sixty five 65 gps points are shown in figure 4. Version 2 is the result of a substantial editing effort by the national geospatial intelligence agency and exhibits welldefined water bodies and coastlines and the absence of spikes and wells single pixel errors.
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