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Coastal Changes and Impacts
The USGS and the National Geospatial-Intelligence Agency (NGA) have collaborated on the development of a notably enhanced global elevation model called the Global Multi-resolution Terrain Elevation Data (GMTED2010), which has replaced GTOPO30 as the elevation dataset of choice for global and continental scale applications.
The U.S. Geological Survey (USGS) and the National Geospatial-Intelligence Agency (NGA) have collaborated on the development of a notably enhanced global elevation model named the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) that replaces GTOPO30 as the elevation dataset of choice for global and continental scale applications. Since the time GTOPO30 was completed, the availability of higher-quality elevation data over large geographic areas has improved markedly. New data sources include global Digital Terrain Elevation Data (DTED) from the Shuttle Radar Topography Mission (SRTM), Canadian elevation data, Spot 5 Reference3D data, and data from the Ice, Cloud, and land Elevation Satellite (ICESat). GMTED2010 provides a new level of detail in global topographic data. The GMTED2010 product suite contains seven new raster elevation products for each of the 30-, 15-, and 7.5-arc-second spatial resolutions and incorporates the current best available global elevation data. The new elevation products have been produced using the following aggregation methods: minimum elevation, maximum elevation, mean elevation, median elevation, standard deviation of elevation, systematic subsample, and breakline emphasis. Metadata have also been produced to identify the source and attributes of all the input elevation data used to derive the output products. Many of these products will be suitable for various regional continental-scale land cover mapping, extraction of drainage features for hydrologic modeling, and geometric and radiometric correction of medium and coarse resolution satellite image data.
The global aggregated vertical accuracy of GMTED2010 can be summarized in terms of the resolution and Root Mean Square Error (RMSE) of the products with respect to a global set of control points (estimated global accuracy of 6 m RMSE) provided by NGA. At 30 arc-seconds, the GMTED2010 RMSE range is between 25 and 42 meters; at 15 arc-seconds, the RMSE range is between 29 and 32 meters; and at 7.5 arc-seconds, the RMSE range is between 26 and 30 meters. GMTED2010 is a major improvement in consistency and vertical accuracy over GTOPO30, which has a 66 m RMSE globally compared to the same NGA control points. In areas where new sources of higher resolution data were available, the GMTED2010 products are substantially better than the aggregated global statistics; however, large areas still exist, particularly above 60 degrees North latitude that lack good elevation data. As new data become available, especially in areas that have poor coverage in the current model, it is hoped that new versions of GMTED2010 might be generated and thus gradually improve the global model.
The 15-arc-second SPOT 5 Reference3D data used for filling SRTM voids in Africa, Central America, Asia, and Australia was graciously provided by Spot Image and IGN.
In addition to the elevation products, detailed spatially referenced metadata containing attribute fields such as coordinates, projection information, and raw source elevation statistics have been generated on a tile-by-tile basis for all the input datasets that constitute the global elevation model.
GMTED2010 Spatially Referenced Metadata
- Download the zipped Spatially Referenced Metadata Shapefile
GMTED2010 Collection-Level Metadata (FGDC)
GMTED2010 Global Grids
- GMTED2010 Technical Documentation Report PDF (3 MB)
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