Science Keywords>LAND SURFACE
ASTER Orthorectified Digital Elevation Model (DEM)Entry ID: AST14DMO
Abstract: The ASTER On-Demand L3 DEM and Orthorectified Images form a multi-file product that contains both the Digital Elevation Model (DEM), and the Orthorectified Image products. Each product delivery includes one DEM data file, and fifteen orthorectified data files in GeoTIFF format.
The ASTER Digital Elevation Model (DEM) product is generated using Bands 3N (nadir-viewing) and 3B ... (backward-viewing) of an ASTER Level-1A image acquired by the Visible Near Infrared (VNIR) sensor. The VNIR subsystem includes two independent telescopes. Together, they produce stereoscopic data. The spectral range of the Band 3 stereo pair is between 0.78 and 0.86 µm with a base-to-height ratio of 0.6, and an intersection angle of about 27.7. There is a time lag of approximately one minute between the acquisition of the nadir and backward-viewing images.
ASTER DEM is a single-band product with 30 meter horizontal postings that is geodetically referenced to the UTM coordinate system, and referenced to the Earth's geoid using the EGM96 geopotential model. The precision of the meets or exceeds accuracy specifications set for the ASTER relative DEMs by the Algorithm Theoretical Basis Document (ATBD). Validation testing has shown that the accuracy of the DEMs is frequently better than 25 meters RMSE xyz.
ASTER Orthorectified Images
The ASTER On-Demand Orthorectified Image products contain imagery transformed from a perspective projection to an orthogonal one. An orthorectified image possesses the geometric characteristics of a map, with near-vertical views for every location. These products are terrain-corrected, provide radiometrically calibrated radiance, and are mapped to the Universal Transverse Mercator coordinate system. The inputs include the following: an ASTER Level-1A Reconstructed Unprocessed Instrument data set; georeferencing information from the ASTER instrument's and Terra platform's ephemeris and attitude data; and an ASTER-derived digital elevation model (DEM). The output product includes fifteen orthorectified ASTER Level-1B calibrated radiance images, one per Band.
Differences between an ASTER Level-1B data set and ASTER Orthorectified Images
• ASTER Level-1B data consist of calibrated radiance in a path-oriented
UTM projection, whereas ASTER orthorectified images are presented in
a north-up UTM projection.
• ASTER orthorectified images possess the geometric characteristics of a
map with near-vertical views for every location, and they also are
• ASTER L1B image dimensions for each of the three sensor systems (VNIR,
SWIR, and TIR) are different because of their different spatial
resolutions; those image dimensions remain constant from one L1B scene
to another. However, ASTER orthorectified image dimensions can vary
from scene to scene. This is because the image dimensions of the ASTER
Digital Elevation Model (DEM) used in the orthorectification process
can vary, and the DEMs image dimensions define the output dimensions
for each of the three sensors orthorectified images.
• The ASTER Level-1B data set is provided in a single multi-file packaged
Hierarchical Data Format (HDF) with specific Earth Observing System
(EOS) conventions. The ASTER orthorectified image file format is
GeoTIFF. The file includes fifteen orthorectified ASTER Level-1B
calibrated radiance images, one for each Band. These image files are
compressed and provided to the user in a single zip file.
V003 data set release date: 2007-03-05
Data Set Characteristics:
Area: ~60 km x 60 km
Image Dimensions: 2500 rows x 2500 columns
File Size: ~191 MB
Projection: Universal Transverse Mercator (UTM)
Data Format: GeoTIFF
Vgroup Data Fields: 1
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Data Set Citation
Dataset Originator/Creator: Land Processes Distributed Active Archive Center (LP DAAC)
Dataset Title: ASTER Orthorectified Digital Elevation Model (DEM)
Dataset Release Date: 2007-03-07
Dataset Release Place: Sioux Falls, South Dakota, USA
Dataset Publisher: U.S. Geological Survey
Version: V003Online Resource: https://lpdaac.usgs.gov/
Start Date: 2007-03-07
Latitude Resolution: 30m
Longitude Resolution: 30m
Horizontal Resolution Range: 30 meters - < 100 meters
Quality Users are advised that ASTER SWIR data acquired from late April 2008 to the present exhibit anomalous saturation of values and anomalous striping. This effect is also present for some prior acquisition periods. Please refer to the ASTER SWIR User Advisory Document (https://lpdaac.usgs.gov/sites/default/files/public/aster/docs/ASTER...) for more details.
Access Constraints See https://lpdaac.usgs.gov/customer_service/aster_access_notice for data access information.
Use Constraints See https://lpdaac.usgs.gov/products/aster_policies for redistribution and citation policies.
Data Set Progress
Distribution Media: HTTP
Distribution Size: ~132 MB
Distribution Format: GeoTIFF
Role: TECHNICAL CONTACT
Phone: (Toll Free) (866) 573-3222
Phone: (605) 594-6116
Fax: (605) 594-6963
Email: LPDAAC at usgs.gov
LP DAAC User Services U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center 47914 252nd Street
City: Sioux Falls
Province or State: SD
Postal Code: 57198-0001
Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) publication references: [available online at http://asterweb.jpl.nasa.gov/asterbiblio20120719.pdf]
National Aeronautics and Space Administration, revised 2006, EOS Reference Handbook, a Guide to NASA's Earth Science Enterprise and the Earth Observing System: Greenbelt, Maryland, Goddard Space Flight Center, 261 p. [available online in pdf format at http://eospso.gsfc.nasa.gov/sites/default/files/publications/2006Re...].
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2013-01-23
Last DIF Revision Date: 2013-08-26