NASA and Japan make ASTER imagery available for free
The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of the instruments on NASA’s Terra satellite. Although it is a NASA satellite, the instrument belongs to Japan’s Ministry of Economy, Trade and Industry (METI). The instrument was launched in 1999 and has captured more than 2.95 million individual scenes since then. On the first of April this year NASA announced that the full catalogue of imagery is being made available to the public at no cost. The instrument, amongst other things, takes stereoscopic images that enables it to calculate altitudes albeit rather low resolution. The elevation data has always been available to the public at no cost.
Mt. Etna, when it erupted in July 2001. The full resolution image and description can be found here.
This image shows the 3D capabilities of ASTER. The full resolution image and description can be found here.
To access the full database of imagery, you can use the MADAS (METI AIST Data Archive System). A really nice feature is that it allows you to download the images as network-linked KML files.
The imagery has a similar resolution to Landsat imagery (approximately 30 m per pixel), so is really only suitable for viewing large scale phenomena. As with Landsat imagery its best use would be to see current events before other satellite imagery becomes available. In December last year we used Landsat imagery to look at the scar made by a tornado near Holly Springs, Mississippi. We found it relatively easy to find an ASTER image of the same region captured on March 28th, 2016, and the scar is still visible. Download this KML file to view it in Google Earth.
The image only covers a small part of the tornado’s track.