ASTGTM v002

ASTER Global Digital Elevation Model


PI: U.S./Japan ASTER Science Team

The ASTGTM.002 dataset was decommissioned as of August 5, 2019. Users are encouraged to use the new improved ASTGTM.003 dataset.

Description

The ASTER Global Digital Elevation Model (ASTGTM) was developed jointly by the U.S. National Aeronautics and Space Administration (NASA) and Japan’s Ministry of Economy, Trade, and Industry (METI).

ASTER is capable of collecting in-track stereo using nadir- and aft-looking near infrared cameras. Since 2001, these stereo pairs have been used to produce single-scene (60 kilometers by 60 kilometers) digital elevation models (DEM) having vertical root mean square error (RMSE) accuracies generally between 10 and 25 meters.

The methodology used by Japan's Sensor Information Laboratory Corporation (SILC) to produce the ASTER GDEM involves automated processing of the entire ASTER Level 1A archive. Stereo-correlation is used to produce over one million individual scene-based ASTER DEMs, to which cloud masking is applied to remove cloudy pixels. All cloud-screened DEMS are stacked and residual bad values and outliers are removed. Selected data are averaged to create final pixel values, and residual anomalies are corrected before partitioning the data into 1 degree by 1 degree tiles.

The ASTER GDEM covers land surfaces between 83°N and 83°S and is comprised of 22,702 tiles. Tiles that contain at least 0.01% land area are included. The ASTER GDEM is distributed as Geographic Tagged Image File Format (GeoTIFF) files with geographic coordinates (latitude, longitude). The data are posted on a 1 arc second (approximately 30 meters at the equator) grid and referenced to the 1984 World Geodetic System (WGS84)/1996 Earth Gravitational Model (EGM96) geoid.

While the ASTER GDEM Version 002 benefits from substantial improvements over ASTER GDEM Version 001, users are nonetheless advised that the products still may contain anomalies and artifacts that will reduce its usability for certain applications because they can introduce large elevation errors on local scales. The data are provided “as is” and neither NASA nor METI/ERSDAC will be responsible for any damages resulting from use of the data.

The generation and basic characteristics of the ASTER GDEM were summarized in a presentation by Tetsushi Tachikawa, et al., at the 2011 Institute of Electrical and Electronics Engineers (IEEE) International Geoscience and Remote Sensing Symposium (IGARSS).

ASTER GDEM data are subject to redistribution and citation policies. See Data Citation and Policies for more information.

Characteristics

Collection and Granule

Collection

Characteristic Description
CollectionTerra ASTER
DOI10.5067/ASTER/ASTGTM.002
File Size~12 MB
Temporal ResolutionMulti-Year
Temporal Extent1999-12-18 to 2011-02-28
Spatial ExtentGlobal
Coordinate SystemGeographic Latitude and Longitude
DatumWGS84/EGM96
File FormatGeoTIFF
Geographic Dimensions1 degree lat x 1 degree lon

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers2
Columns/Rows3601 x 3601
Pixel Size30 meter

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
DEM Digital Elevation Model Meters 16-bit signed integer -9999 N/A -500 to 9000 (0 at sea level) N/A
NUM¹ Quality Assurance (Number of scenes) N/A 16-bit signed integer -1, -2,-5,-6,-11 N/A 0 to 200 N/A

¹A negative value for the NUM layer identifies the source of reference data used to fill voids.

Quality Assurance Fill Values

Value Description
-1 SRTM3 V003
-2 SRTM3 V002
-5 NED
-6 CDED
-11 Alaska DEM

Product Quality

The ASTER GDEM Version 2 Validation Summary provides additional information on product quality.

Known Issues

ASTER GDEM v2 tiles overlap by one pixel to the north, south, east, and west of the tile perimeter. In most cases the overlapping edge pixels have identical pixel values, but in some cases they do not. Users are reminded that because there are known inaccuracies and artifacts in the dataset, to please use the product with awareness of these limitations. The data are provided "as is" and neither National Aeronautics and Space Administration (NASA) nor Ministry of Economy, Trade, and Industry (METI)/Earth Resources Satellite Data Analysis Center (ERSDAC) will be responsible for any damages resulting from use of the data.

Documentation

Using the Data

E-Learning

How to Access NASA ASTER and MODIS Data with Earth Explorer Tool

Observing Land from Space: Interacting with Geospatial Data from NASA's LP DAAC

Using NASA Remote Sensing for Disaster Management

Data In Action

Better Understanding the Hot Topic of Lahars through ASTER

Highlights from the Literature: January to March 2018

Highlights from the Literature: July to September 2016

The NASA DEVELOP National Program Spring/Summer 2014

Highlights from the Literature: July to September 2014

Highlights from the Literature: October to December 2015

Highlights from the NASA DEVELOP National Program Summer 2015 Term

The Role of Terrain Data

Highlights from the Literature: October to December 2014

Highlights from the Literature: July to September 2018

Highlights from the Literature: April to June 2019

Tools

Citation

DOI: 10.5067/ASTER/ASTGTM.002

About the Image