23 May 2016

ASTER Global Digital Elevation Model (GDEM)

Those who are looking for higher resolution DEM, I have a very good news to convey.

All ASTER data products are now available at no charge to all users

Now, NASA/METI released the 30m global (83°N and 83°S and is composed of 22,600 1°-by-1° tiles) ASTER GDEM based on 1,264,118 single ASTER dems from 1.4 million scenes in total. 95% vertical ci: 20 meters, 95% horizontal ci: 30 meters)

ASTER GDEM is an easy-to-use, highly accurate DEM covering all the land on earth, and available to all users regardless of size or location of their target areas. Anyone can easily use the ASTER GDEM to display a bird's-eye-view map or run a flight simulation, and this should realize visually sophisticated maps. By utilizing the ASTER GDEM as a platform, institutions specialized in disaster monitoring, hydrology, energy, environmental monitoring etc. can perform more advanced analysis.

The methodology used to produce the ASTER GDEM involved automated processing of the entire 1.5-million-scene ASTER archive, including stereo-correlation to produce 1,264,118 individual scene-based ASTER DEMs, cloud masking to remove cloudy pixels, stacking all cloud-screened DEMs, removing residual bad values and outliers, averaging selected data to create final pixel values, and then correcting residual anomalies before partitioning the data into 1°-by-1° tiles. It took approximately one year to complete production of the beta version of the ASTER GDEM using a fully automated approach.

The ASTER GDEM covers land surfaces between 83°N and 83°S and is composed of 22,600 1°-by-1° tiles. Tiles that contain at least 0.01% land area are included. The ASTER GDEM is in GeoTIFF format with geographic lat/long coordinates and a 1 arc-second (30 m) grid of elevation postings. It is referenced to the WGS84/EGM96 geoid. Pre-production estimated accuracies for this global product were 20 meters at 95 % confidence for vertical data and 30 meters at 95 % confidence for horizontal data.

This was produced using ASTER data acquired from the start of observation to the end of August, 2008 in cooperation with the Japan-US ASTER Science Team. ASTER GDEM is now released and its distribution started, after the validation and the distribution site design.

ASTER GDEM tiles can be downloaded electronically from ERSDAC by visiting the link below: This web-based search system has 4 methods for tile selection. You can select tiles with one of the following methods.
  • Select tiles directly
  • Select tiles by polygon
  • Select tiles by shapefile
  • Select tiles by coordinates

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