ASTER Global DEMs

Description

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) was developed as a joint effort by NASA (the US National Aeronautics and Space Administration) and METI (Japan's Ministry of Economy, Trade and Industry). The GDEM product is produced from stereo pair images, with vertical RMS error of approximately 10 to 25 meters. There are currently two versions of this product, called GDEM 1 (released in 2009) and GDEM 2 (released in 2011). Although it has been argued that the quality of these DEMs is not as good as SRTM, it has a greater global coverage spanning -83 (south) to 83 (north) degrees of latitude. This exceeds the SRTM coverage of -56 (south) to 60 (north) degrees of latitude.

Grid Information

Coord. System: Geographic decimal degrees, fixed-angle
Cell Size: 1 arcsecond (1/3600 degree or 1/60 arcminute)
(roughly 30 meters at the equator)
Pixel-center registered
Tile Dimensions: 3601 columns x 3601 rows (1 tile)
Tile Span: 1 degree (longitude) x 1 degree (latitude), 1 tile
(22,702 tiles, for latitudes between -83 and 83)
Data Type: 2-byte integer, signed
Horizontal Datum: WGS 84
Vertical Datum: EGM 96
Vertical Units: meters
Nodata Value: -9999
Formats: GeoTIFF format (.tif). May have a companion "world file" (.tfw)

How to Import

Choose Import DEM → GeoTIFF from the File menu and then select the file, which will usually have the filename extension "*.tif".

Data Source

ASTER imagery from NASA (U.S. National Aeronautics and Space Administration) and METI (Japan's Ministry of Economy, Trade and Industry)

Data Availability

Data can be downloaded from the USGS Land Processes Distributed Active Archive Center (LP DAAC).

Web Sites

Main Page: https://lpdaac.usgs.gov/products/aster_products_table/astgtm

Other ASTER Products: https://lpdaac.usgs.gov/products/aster_products_table

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