Advanced Spaceborne Thermal Emission and Reflection Radiometer

ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is one of the five scientific instruments on board the launched by NASA on 18 December 1999 earth observation satellites Terra. The Japanese-built instrument shows since February 2000 data. It orbits in a nahpolaren orbit the Earth at an altitude of 705 km.

ASTER takes high resolution images in 14 channels of the electromagnetic spectrum from visible light to thermal infrared on, the resolution is about 15 to 90 meters per pixel. From this altitude, surface temperature, reflectance and emissivity of the observed land part can be derived. Channel 3, which takes in the near infrared spectral range, is doubled. The first channel 3N ( nadir) is like the rest of the earth's surface vertically below the platform from. The second channel 3B takes the same surface some time later by 27.6 ° rotated backward on. In this way creates a stereo image that you can use in calculating a digital elevation model ( as for the example of Mount Etna to see ).

Digital elevation data from ASTER with a spatial resolution of 30 m to 83 ° latitude represents NASA for download, free of charge for research and education. For comparison: SRTM data are Open Data and thus free for use for any purpose, but are only within 60 ° of latitude, outside the U.S. only with a resolution of 90 m.

There are now more accurate satellite- generated elevation models, such as the instrument PRISM satellite ALOS with a horizontal resolution of 5 m, which are conveniently accessible to researchers, or the more accurate panchromatic stereo images of commercial satellites WorldView-1 and WorldView -2 with a horizontal resolution of ~ 1m. The advantage of Aster consists in the consistency of the data set.

Version 2

Since October 16, 2011, version 2 is ready. Some rough data errors have been fixed and there are to see more details of the earth's surface.