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    This data was produced under contract for Alberta Agriculture and Forestry, Forest Management Branch in 2015-2016. Variables used were elevation, aspect, slope, landscape mesotopography (e.g. ridge, upper slope, etc). DEM was used where there was no LiDAR coverage, with a resolution of 25 m2 pixels. Canopy height was not included in this model because it was a product generated by LiDAR. In these files there is a report assessing accuracy of the models compared with field observation data; detailed accuracy data by township is available upon request.

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    This data was produced under contract for Alberta Agriculture and Forestry, Forest Management Branch in 2015-2016. Variables used were elevation, aspect, slope, landscape mesotopography (e.g. ridge, upper slope, etc). DEM was used where there was no LiDAR coverage, with a resolution of 25 m2 pixels. Canopy height was not included in this model because it was a product generated by LiDAR. In these files there is a report assessing accuracy of the models compared with field observation data; detailed accuracy data by township is available upon request.

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    Landmælingar Íslands hafa unnið nýtt landhæðarlíkan af Íslandi. Um uppfærslu á eldra líkani er að ræða þar sem nýleg gögn af ólíkum uppruna þekja um 39.100 km2 eða um 38% landsins. Stærsta samfellda uppfærslan nær frá Suðurlandi til norðausturs, austur fyrir Egilsstaðir.Hæðarlíkanið hefur 10 x 10 m myndeiningar. Helsu nýleg gögn eru (sjá staðsetningu á meðfylgjandi smámynd hér fyrir neðan): 1) IPY-Lidargögn fyrir jökla landsins frá árunum 2007-2012, 15144 km2, LE90: 2,65 m. 2) Gögn úr 5-m-hæðarlínum, 10736 km2, LE90: 3,9 m. 3) Emisar radargögn, 4536 km2, LE90: 3,2 m. 4) Gögn úr 10-m-hæðarlínum, 2938 km2, LE90: 8,48 m, 5) SwedeSurvey photogrammetry gögn, 1433 km2, LE90: 2,60 m, 6) Gögn úr mælikvarða 1:25.000, 1152 km2, LE90: 3,8 m, 7) Bresk lidargögn (Dr. Susan Conway, Open University), 532 km2, LE90: 0,96-4,63 m. Líkaninu fylgir hæðarskygging, þ.e. upphleypt mynd af landinu en slíkar myndir eru gjarnan notaðar sem undirlag til að draga fram eða leggja áherslu á landslag. The National Land Survey of Iceland has made a new DTM of Iceland. The DTM is an upgrade of an earlier DTM where recent data, that vary in origin, cover 39.100 km2 or some 38% of the country. The DEM has pixel resolution of 10 x 10 m with. The main recent data are (see location on figure below): 1) IPY-lidar data for the glaciers of Iceland (surveyed in the years 2007 to 2012), 15144 km2, LE90: 2,65 m. 2) Data from 5-m-contour lines, 10736 km2, LE90: 3,9 m. 3) Emisar radar data, 4536 km2, LE90: 3,2 m. 4) Data from 10-m-contour lines, 2938 km2, LE90: 8,48 m, 5) SwedeSurvey photogrammetic data, 1433 km2, LE90: 2,60 m, 6) 1:25.000 contour data, 1152 km2, LE90: 3,8 m, 7) British lidar data (courtesy of Dr. Susan Conway, Open University), 532 km2, LE90: 0,96-4.63 m.The DTM is accompanied by a hillshade or a relief image of Iceland. Hillshade images are commonly used as a layer beneath maps or data to emphasize landscape.

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    The USGS 3D Elevation Program (3DEP) Index service from The National Map shows two general categories of downloadable elevation data: (1) digital elevation model (DEM) datasets at standardized horizontal resolutions, and (2) elevation source data including that used to produce standard DEMs, and additional datasets derived from ifsar in Alaska only. Distributable DEM products include: 2 arc-second (in Alaska only); 1 arc-second; 1/3 arc-second; 1/9 arc-second; 5 meter (in Alaska only); and 1 meter. The 2-, 1-, and 1/3-arc-second products are staged for download in 1x1 degree tiles in ArcGrid, GridFloat, or IMG formats, while 1/9 arc-second products are staged in 15x15 minute tiles in IMG format only. The 5-meter products are staged for download in ArcGrid only as a single mosaicked raster to each project extent. The 1-meter products are staged in 10,000x10,000 meter tiles in IMG format only. Distributable elevation source data include: lidar point clouds (LPC) in LAS format for various parts of the U.S., and ifsar-derived digital surface models (DSM) and orthorectified radar images (ORI) in TIFF format in Alaska only. For additional information on the 3DEP, go to http://nationalmap.gov/3DEP/index.html.

  • The USGS 3D Elevation Program (3DEP) Bare Earth DEM Dynamic service is based on multi-resolution USGS DEM sources and provides dynamic functions for visualization. These functions include: Hillshade, Aspect Map, Hillshade Stretched, Multi-directional Hillshade, Slope Map, Elevation Tinted Hillshade, Contour. In addition the OGC Web Map Service (WMS) and Web Coverage Service (WCS) interfaces are enabled.