On the next to last day of June, NASA and Japan’s Ministry of Economy, Trade and Industry released a new topographic map and dataset that constitutes the most comprehensive ever publicly available map of surface elevations of the earth. The collection, technically named the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM), is available on the NASA website here, where it is also described in greater detail. The dataset and model were created by processing and stereo-correlating the 1.3 million-scene ASTER archive of optical images collected by NASA’s Terra satellite, and covers the land surface of the earth between 83 degrees North and 83 degrees South latitudes at a resolution of 30 meters. It is presented as a set of 23,000 tiles of one-degree-by-one- degree. In the colorized version, low elevations are purple, medium elevations are greens and yellows, and high elevations are orange, red and white. For further information, see the NASA site referenced above or see Science Daily’s summary of the release here.
For a demonstration of how the model might be used in more popular applications, check out NASA’s Cruising Over California.