What we can see with the GEO Grid / ASTER
Remote sensing is to observe and examine an object or space on the ground from some distance. For example, observation from a balloon or plane up above in the air is in fact remote sensing, but here we define remote sensing as observation with an instrument installed on an artificial satellite.
Remote sensing constantly provides us with objective information data about the earth. The GEO Grid Project accumulates the data from a sensor, called ASTER, which has been collecting data since 2000. From this global observation data we can extract various information about the earth from various viewpoints. For example data on the surface temperature distribution of land, reflectivity, composition, etc. are available. We can also get secondary information by overlapping the data with other information such as geological maps.
The GEO Grid Project is constructing a high-precision digital map using raw data from ASTER. Many users are expected to re-discover the earth from this map.
Examples
What's ASTER?
ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is an advanced optical sensor with 14 bands from visible to thermal infrared light regions, and collects image data that is useful for various geoscience fields. ASTER was installed in Terra, a satellite built as part of NASA's Earth Observing System (EOS) project launched into space from the Vandenberg air base in California, the United States, in December 1999. ASTER continues the observation today.
The ASTER sensor consists of three sub systems, visible light near infrared (VNIR), short wave infrared (SWIR), and thermal infrared (TIR), to cover a wide range of wavelengths from visible to thermal infrared light. The VNIR system's detector can catch light coming from beneath and from a backward direction to allow stereo observation for developing a DEM (Digital Elevation Model).
In the six and half years since the launching of ASTER, more than 100TB of observation data have been archived and are now ready for use. The GEO Grid has a plan to archive all the ASTER data by March 2007 to make them available. In particular, the GEO Grid aims to use the data to provide 15m-resolution DEM of all land on the earth.