The U.S. Geological Survey (USGS) and the National Geospatial-Intelligence Agency (NGA) have collaborated on the development of an improved global elevation model, the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010). GMTED2010 replaces the widely used, 15-year old GTOPO30 terrain model as its best available global digital elevation model. Useful for regional, continental, and global-scale applications, GMTED2010 is derived from numerous higher quality elevation data sources that were unavailable at the time GTOPO30 was developed. The new sources include near-global Digital Terrain Elevation Data (DTED) from the Shuttle Radar Topography Mission (SRTM); Canadian elevation data; SPOT 5 Reference 3D data; data from NASA's Ice, Cloud, and land Elevation Satellite (ICESat); and updated Antarctica and Greenland terrain models. GMTED2010 is a significant improvement in scope, quality and consistency over the single 30-arc-second-resolution elevation data product represented by GTOPO30. The new elevation dataset comprises a suite of seven raster elevation products at spatial resolutions of 30, 15 and 7.5 arc-seconds (approximately 1 kilometre, 500 metres and 250 metres, respectively), all generated by aggregating the highest resolution data available in a given geographic area. The seven new raster elevation products have been produced using: 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. GMTED2010 elevations are referenced to the World Geodetic System 1984 (WGS 84) horizontal datum and, in most cases, to the Earth Gravitational Model 1996 (EGM96) geoid as the vertical datum. The global aggregated vertical accuracy of GMTED2010 can be summarised in terms of the resolution and root mean square error (RMSE) of the products with respect to a global set of control points provided by NGA. At 30 arc-seconds, for example, the GMTED2010 RMSE ranges between 25 and 42 metres compared to GTOPO30, which has an RMSE of 66 metres globally with respect to the same control points. All of the GMTED2010 data products are publicly available with no redistribution restrictions. GMTED2010 data can be accessed and downloaded online . For further details on GMTED2010, refer to USGS Open File Report 2011-1073 . Specific questions about GMTED2010 can be emailed to gmted2010@usgs.gov .
北京天津河北山西内蒙古辽宁 吉林黑龙江上海江苏浙江安徽 福建江西山东河南湖北湖南 广东广西海南重庆四川贵州 云南西藏陕西甘肃青海宁夏 新疆香港澳门台湾 批量方便 下载地址： http://item.taobao.com/item.htm?id=13307915563 V2版本发布了，数据明显比V1版本的要大，质量 质量报告如下： http://www.ersdac.or.jp/GDEM/E/4_1.html (Example 1) Enhanced ground resolution: The Northern Alps, Japan The resolution was greatly improved by the new GDEM generation algorithm, from equivalent to about 120m (Version 1) to 70 m (Version 2) . Ver.2 Ver.1 Enhanced ground resolution (Example 2) Reduction of voids: High-latitude areas Voids observed at high latitudes in Version 1 are removed significantly in Version 2 after addition of 350,000 new scenes Ver.2 Ver.1 Reduction of voids (black indicates data void) (Example 3) Flat lake surface: Lake Nicaragua Lake surface appears completely flat in Version 2 by the new GDEM generation algorithm. Ver.2 Ver.1 Flat lake surface (Example 4) Correction of anomalies: Northeastern part of southern Africa Anomalies caused due to lack of observation data disappeared after addition of 350,000 new scenes. Ver.2 Ver.1 Corrected step anomalies
NASA10月17日的消息。之前的版本是2009年6月发布的；在其基础上增加了26万幅立体像对以提高空间分辨率和三维精度。数据是FREE的，免费下载。 http://www.jpl.nasa.gov/news/news.cfm?release=2011-320 NASA, Japan Release Improved Topographic Map of Earth October 17, 2011 PASADENA, Calif. - NASA and Japan released a significantly improved version of the most complete digital topographic map of Earth on Monday, produced with detailed measurements from NASA's Terra spacecraft. The map, known as a global digital elevation model, was created from images collected by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, instrument aboard Terra. So-called stereo-pair images are produced by merging two slightly offset two-dimensional images to create the three-dimensional effect of depth. The first version of the map was released by NASA and Japan's Ministry of Economy, Trade and Industry (METI) in June 2009. "The ASTER global digital elevation model was already the most complete, consistent global topographic map in the world," said Woody Turner, ASTER program scientist at NASA Headquarters in Washington. "With these enhancements, its resolution is in many respects comparable to the U.S. data from NASA's Shuttle Radar Topography Mission, while covering more of the globe." The improved version of the map adds 260,000 additional stereo-pair images to improve coverage. It features improved spatial resolution, increased horizontal and vertical accuracy, more realistic coverage over water bodies and the ability to identify lakes as small as 0.6 miles (1 kilometer) in diameter. The map is available online to users everywhere at no cost. "This updated version of the ASTER global digital elevation model provides civilian users with the highest-resolution global topography data available," said Mike Abrams, ASTER science team leader at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "These data can be used for a broad range of applications, from planning highways and protecting lands with cultural or environmental significance, to searching for natural resources." The ASTER data cover 99 percent of Earth's landmass and span from 83 degrees north latitude to 83 degrees south. Each elevation measurement point in the data is 98 feet (30 meters) apart. NASA and METI are jointly contributing the data for the ASTER topographic map to the Group on Earth Observations, an international partnership headquartered at the World Meteorological Organization in Geneva, Switzerland, for use in its Global Earth Observation System of Systems. This "system of systems" is a collaborative, international effort to share and integrate Earth observation data from many different instruments and systems to help monitor and forecast global environmental changes. ASTER is one of five instruments launched on Terra in 1999. ASTER acquires images from visible to thermal infrared wavelengths, with spatial resolutions ranging from about 50 to 300 feet (15 to 90 meters). A joint science team from the United States and Japan validates and calibrates the instrument and data products. The U.S. science team is located at JPL. NASA, METI, Japan's Earth Remote Sensing Data Analysis Center (ERSDAC), and the U.S. Geological Survey validated the data, with support from the U.S. National Geospatial-Intelligence Agency and other collaborators. The data are distributed by NASA's Land Processes Distributed Active Archive Center at the U.S. Geological Survey's Earth Resources Observation and Science Center in Sioux Falls, S.D., and by ERSDAC in Tokyo. Users of the new version of the ASTER data products are advised that while improved, the data still contain anomalies and artifacts that will affect its usefulness for certain applications. Data users can download the ASTER global digital elevation model at: https://lpdaac.usgs.gov/ or http://www.ersdac.or.jp/GDEM/E/4.html . For more information about ASTER, visit: http://asterweb.jpl.nasa.gov/ . For more information on NASA's Terra mission, visit: http://www.nasa.gov/terra .
在 尺度效应例5：DEM 评论中，网友 silversoft 问：胡老师一直研究的问题似乎主要是解决两种不同分辨率的DEM模型之间的高程值的转化或综合问题， 我觉得这样理解是靠谱的。但是老邪毕竟是外行。好在胡鹏教授也看博客的，所以在给我的email里有段话我感觉间接回复了网友 silversoft ： 你的博客中，有 Simonett常提遥感的多分辨率的特点和地表复杂性造成的尺度效应是遥感科学的核心科学问题，我认为：整个GI都有多分辨率、多尺度效应都如此。因而综合作为哲学上、认识论普适方法，在整个GI也普适。我在 DEM上体会很深： 不同对象，有不同的综合指标，DEM上是高程特征，雨量是总量...。矢量的多分辨率很难搞，比如地形图上等高线综合,百年用手工，今天也基本如此； 而DEM数字综合，实质上已完全解决了此问题，也即栅格的综合，按指标耒会比较顺。矢栅统一、数字综合的重要意义可能会很大。 老邪赞成。多年以前，矿大（徐州？）就有一位老先生建议搞尺度学。我感觉我们哲学上弱了一点，后来在网上呼吁学哲学的网友指导，也没人响应。希望胡鹏教授的研究能深入下去。 胡鹏教授的部分论著： Hu Peng, Liu Xiaohang, Hu Hai, 2009. Accuracy Assessment of Digital Elevation Models based on Approximation Theory , Photogrammetric Engineering and Remote Sensing,75(1): 49-56; Hu Peng, Liu Xiaohang,Hu Hai, 2009. Isomorphism in Digital Elevation Models and Its Implication to Interpolation Functions , Photogrammetric Engineering and Remote Sensing, 75(6):713-721; Hu Hai, Gao Jun, Hu Peng, 2009.The Digital Generalization Principle of Digital Elevation Model. International Symposium on Spatial Analysis, Spatial-Temporal Data Modeling, and Data Mining,Proc. of SPIE Vol. 7492, 749221; Wu yanlan, Liu yongqiong,et.al.2009. Flow paths tracing from raster contours using distance transform. International Symposium on Spatial Analysis, Spatial-Temporal Data Modeling, and Data Mining, Proc. of SPIE Vol. 749255; 胡鹏,白轶多,胡海,2009. 数字高程模型（DEM）生成中的序同构问题 ,武汉大学学报(信息科学版)34（3）:352-357; 胡海,杨传勇,胡鹏,2007. DEM 最优线性生成技术MADEM ，华中科技大学学报(自然科学版) ,35（6）:118-121; 胡鹏,高俊,2009. 数字高程模型的数字综合原理研究 . 武汉大学学报(信息科学版 ),34(8): 940-942;
标签: DEM
