This Global Digital Elevation Model, or GDEM, is a product of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The image was released on June 29, 2009, and was created by processing and stereo-correlating the 1.3 million-scene ASTER archive of optical images, covering Earth's land surface between 83 degrees North and 83 degrees South latitudes. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change. Image Credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Buy this as a superb wall poster, a canvas print or a framed print.