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ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is one of the sensors operating on board of TERRA, a satellite launched in December 1999 as part of NASA's Earth Observing System ( http://ASTERweb.jpl.nasa.gov/ ). ASTER covers a wide spectral region with 14 bands from the visible to the thermal infrared with high spatial, spectral and radiometric resolution. The spatial resolution varies with wavelength: 15 m in the visible and near infrared (VNIR - 0.55 to 0.80um ), 30 m in the short wave infrared (SWIR - 1.65 to 2.4um), and 90 m in the thermal infrared (TIR - 8.3 to 11.32um). |
An additional band is
the key to produce Digital Elevation Models. This band (named 3B) works
at the same spatial resolution of ordinary band 3 (NIR), but at a backward
angle of approximately 28 degrees, producing a stereo pair for each and
every ASTER image. Each ASTER scene covers an area of 60 x 60 km, and
the sensor has up to 8.55 degrees of pointing capabilities.
Click here to
see a video simulation about Aster´s scanning swath.
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The TERRA satellite crosses the equator at about 10:30 am local time, about half an hour after the Landsat corssing, on a similiar orbit (98.2 degrees inclination).
Aster´s products include:
- spectral reflection and radiation of Earth´s surface;
- surface temperature and emissivity;
- digital elevation maps of stereo images;
- vegetation and surface composition maps;
- cloud consequences, sea ice and polar ice;
- natural disasters (volcanos, hurricanes, etc.) observation.