
	Where results make sense

Topic: Digital elevation model

Related Topics

Altitude

Topography

Mill Ends Park

Adair Village, Oregon

Broomfield, Colorado

Ferris wheel

USS Colorado

Portland, Oregon

Oregon

Multnomah County, Oregon

Alluvium

Exploding whale

Bend, Oregon

Bedrock

Aimee Mann

In the News (Tue 15 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Digital elevation model - Wikipedia, the free encyclopedia
		A digital elevation model (DEM) is a representation of the topography of the Earth or another surface in digital format, that is, by coordinates and numerical descriptions of altitude.
		Digital elevation models may be prepared in a number of ways, but they are frequently obtained by remote sensing rather than direct survey.
		One powerful technique for generating digital elevation models is interferometric synthetic aperture radar; two passes of a radar satellite (such as RADARSAT-1) suffice to generate a digital elevation map tens of kilometers on a side with a resolution of around ten meters.
	en.wikipedia.org /wiki/Digital_elevation_model (364 words)

	Digital elevation model -- Facts, Info, and Encyclopedia article (Site not responding. Last check: 2007-09-16)
		A DEM may or may not be accompanied by information about the (Low-growing plants planted in deep shade or on a steep slope where turf is difficult to grow) ground cover.
		Digital elevation models may be prepared in a number of ways, but they are frequently obtained by (Click link for more info and facts about remote sensing) remote sensing rather than direct (A detailed critical inspection) survey.
		Submarine elevation (known as (Measuring the depths of the oceans) bathymetry) data can be generated using satellite based sensors or ship mounted depth soundings.
	www.absoluteastronomy.com /encyclopedia/d/di/digital_elevation_model.htm (361 words)

	USGS Digital Elevation Model (DEM)
		Elevations are recorded by stereomodel digitizing of contours, in which digital contours are acquired on stereoplotters equipped with three-axis digital recording modules.
		DEM data of low-relief terrain or generated from contour maps with intervals of 10 feet or less are recorded in feet while DEM data of moderate to high-relief terrain or generated from maps with terrain contour intervals greater than 10 feet are generally recorded in meters.
		A digital elevation model is composed of integer values representing a gridded form of a topographic map hypsography overlay.
	edc.usgs.gov /guides/dem.html (3299 words)

	US GeoData Digital Elevation Models, Fact Sheet 040-00 (April 2000)
		DEM data for 1-degree units are collected from topographic map sources, ranging from the 7.5-minute map series to the 1- by 2-degree map series, or from photographic sources by using image correlation systems.
		DEM data are produced by the National Imagery and Mapping Agency (NIMA) in l- by 1-degree units that correspond to the east or west half of the USGS 1- by 2-degree topographic quadrangle map series (1:250,000-scale) for all of the United States and its territories.
		DEM data accuracy is derived by comparing linear interpolation elevations in the DEM with corresponding map location elevations and computing the statistical standard deviation or root-mean-square error (RMSE).
	mac.usgs.gov /isb/pubs/factsheets/fs04000.html (1287 words)

	USGS TerraWeb: Flagstaff Atlas: Digital Elevation Model Images
		A Digital Elevation Model (DEM) is a data set that can be used to complement remotely sensed satellite images; it is a representation of the topography/elevation of an area on a pixel by pixel basis in a raster image format.
		The digital number at a given DEM pixel is equal to the elevation at that location (usually in feet or meters).
		DEM data for fifteen different quadrangles were digitally mosaicked to cover the same area covered by the Landsat TM images.
	terraweb.wr.usgs.gov /projects/Flagstaff/dem.html (1125 words)

	DEM, Digital Elevation Model. (Site not responding. Last check: 2007-09-16)
		A Digital Elevation Model (DEM) is digital cartographic/geographic data in raster form.
		The terrain elevations for ground positions are sampled at regularly spaced horizontal intervals.
		DEMs are derived from hypsographic data (contour lines) and/or photogrammetric methods using USGS 7.5-minute, 15-minute, 2-arc-second (30- by 60-minute), and 1-degree (1:250,000-scale) topographic quadrangle maps.
	craterlake.wr.usgs.gov /dem.html (96 words)

	USGS Digital Elevation Models
		A digital elevation model (DEM) is a digital file consisting of terrain elevations for ground positions at regularly spaced horizontal intervals.
		DEM's may be used in the generation of three-dimensional graphics displaying terrain slope, apsect (direction of slope), and terrain profiles between selected points.
		A DEM file is organized into a series of three records, A, B, and C. The A record contains information defining the general characteristics of the DEM, including its name, boundaries, units of measurement, minimum and maximum elevations, number of B records, and projection parameters.
	rockyweb.cr.usgs.gov /elevation/dpi_dem.html (600 words)

	Digital Elevation Model (DEM).
		A Digital Elevation Model (DEM) is a digital cartographic/geographic dataset of elevations in xyz coordinates.
		These 10-m DEMs come from the same source data, the hypsographic DLGs, which have 40 ft contours.
		The following files are a complete DEM for the Lake Tahoe Basin, created from the 18 7.5-minute quadrangles of 10-m DEMs and the bathymetric elevation model.The 18 DEM quadrangles that cover the Lake Tahoe Basin have been mosaicked together.
	tahoe.usgs.gov /DEM.html (299 words)

	What is a DEM (Digital Elevation Model) (Site not responding. Last check: 2007-09-16)
		Digital Elevation Models are data files that contain the elevation of the terrain over a specified area, usually at a fixed grid interval over the surface of the earth.
		Elevations other than at the specific grid point locations are not contained in the file.
		When an elevation is calculated at locations other than the actual grid points, some method of interpolation from the known grid points is used.
	www.softwright.com /dem.html (396 words)

	Digital Elevation Model (Site not responding. Last check: 2007-09-16)
		Digital Elevation Models (DEMs) are produced by the U.S. Geological Survey in a number of different resolutions.
		Each county DEM is composed of all the 1:24,000 DEMs that fall within the county.
		These DEMs are merged into a single DEM and have been clipped to the county boundary using a 1:24,000 county coverage of Virginia.
	www.radford.edu /~geoserve/dem_main_page.html (124 words)

	DEM (digital elevation model)
		DEM data which has been converted to the SDTS format is referred to as "SDTS DEMs"
		RMSE of one-half contour interval is the maximum permitted.
		RMSE of one-third of the contour interval is the maximum permitted.
	www.vterrain.org /Elevation/dem.html (502 words)

	Digital Elevation Model
		An important part of the early project was the creation of a Digital Elevation Model (DEM) for the region.
		Digital elevation model from 1:100000 scale Belgium maps.
		Once we had a useable DEM, we could begin the process of overlaying the imagery onto the DEM to produce realistic three dimensional views of the region, as well as digital fly-throughs.
	www.informatics.org /gorilla/dem.html (312 words)

	Digital Elevation Model of Denmark (Site not responding. Last check: 2007-09-16)
		The digital elevation model of Denmark is comuputed from a complete set of digitised 5m elevation contours and is defined in a spatial resolution of approximately 200m.
		The RMS (root mean square) accuracy of the elevation in the Digital Elevation Model is calculated to 1-2 m.
		The shaded relief image shows the topography of Denmark in striking but also strongly exaggerated detail (the highest peak of Denmark is slightly lower than 200 m).
	www.kms.dk /research/geodesy/geoid/digitaldk_en.html (73 words)

	[No title] (Site not responding. Last check: 2007-09-16)
		The elevation values are expressed in meters with respect to mean sea level (MSL), in accordance with the North American Datum of 1983 (NAD83).
		The SRTM-1 (1 arc-second) and SRTM-3 (3 arc-second) digital elevation models are being developed from the SRTM C-band radar observations for selected regions to satisfy the needs of NASA related projects and to speed the evaluation of acquisition and processing and applications algorithms.
		The quality of the ASTER DEM data is excellent, equivalent in resolution to USGS 30m SDTS DEM data and has free coverage for a large portion of the Globe.
	www.globalmapper.com /formats.html (3764 words)

	[No title] (Site not responding. Last check: 2007-09-16)
		Elevation data located on the degree lines (all four sides) correspond with the same profiles on adjoining DEM blocks.
		This original DEM of Australia was calculated by Moore and Simpson (1982) using the minimum curvature interpolation procedure of Briggs (1974) applied to approximately 320,000 point elevations.
		The DEM is at 50m resolution and has a claimed RMS error of less than 2.5m, comparable with equivalent digital data from the UK Ordnance Survey.
	www.geo.ed.ac.uk /geoinfo/dem.send (12599 words)

	USGS SDTS format Digital Elevation Model data (DEM)
		Instead, they were derived from the most primitive but reliable source of DEM data that we have: paper topographic maps.
		Using USGS DEMs in ArcView GIS - As GIS technology goes mainstream, we at the GeoCommunity have found a dramatic increase in the number of people downloading freely available data only to then be stumped when it comes to actually viewing or using the data.
		The new STDS DEM data can be used by ArcView3.2 but requires editing of the xxxxIDEN.DDF file - this posting to the discussion board provides details.
	data.geocomm.com /dem (1169 words)

	Alaska North Slope 100 m Digital Elevation Model (DEM) (Site not responding. Last check: 2007-09-16)
		This data set is a 100-m resolution digital elevation model (DEM) for the Brooks Range and the North Slope of Alaska.
		The DEM was created by merging 100 National Elevation Dataset DEM tiles for areas of Alaska north of 67 degrees north latitude.
		The resulting DEM is in the Alaska Albers conical equal area projection, using the North American Datum of 1927 (NAD27).
	www.nsidc.org /data/arcss301.html (142 words)

	Digital Elevation Modeling and Mapping Digital Elevation Model
		A Digital Elevation Model is an ASCII or binary file that contains only spatial elevation data in a regular gridded pattern in raster format.
		The generation of 3D renderings from Digital Elevation Model data by the method outlined here, while not difficult, requires a certain level of skill and art.
		Pov-Ray is still a powerful tool for terrain modeling and offers virtually the same flexibity as Open GL programming with a more friendly user interface, so this application is worth looking at as well.
	www.terrainmap.com /rm3.html (991 words)

	UNIT 38 - DIGITAL ELEVATION MODELS
		Digital Elevation Modeling -- Creating a TIN; viewing a TIN; Converting a TIN to polygon coverage.
		digital terrain model or DTM may actually be a more generic term for any digital representation of a topographic surface, but it is not so widely used
		Digital Elevation Models, Data Users Guide 5, US Department of the Interior, USGS, Reston, VA. Describes the creation and data structures of USGS DEMs in detail.
	www.geog.ubc.ca /courses/klink/gis.notes/ncgia/u38.html (2287 words)

	USGS TerraWeb for Kids: Make your own 3D Elevation Model!
		The reason the elevation model is whiter where it is higher in elevation is because in the digital (computer) file the elevation is represented by a number, but to display the image on the monitor, the computer needs to use a tone (level of brightness).
		In the digital file, an image is also stored in rows and columns, except as numbers, not tones or dots.
		A very low number in a digital elevation model, like 10, is dark, and a high number, like 240, is bright, All the numbers in between are displayed as shades of grey.
	terraweb.wr.usgs.gov /TRS/kids/VRML.html (586 words)

	Digital Elevation Model
		Digital Elevation Models (DEMs) consist of a raster grid of regularly spaced elevation values that have been primarily derived from the USGS topographic map series.
		The NED is a seamless raster dataset developed by merging the highest-resolution, best-quality 1:24,000-scale Digital Elevation Model (DEM) data available across the United States.
		From this DEM, a shaded relief model was created and is available in the DEM folder as well.
	pubs.usgs.gov /dds/dds-81/Intro/TopographicData/DEM/DEM.html (77 words)

	Vicmap Elevation - Digital Elevation Model (DEM)
		Vicmap Elevation - Digital Elevation Model (DEM) is a statewide, high-resolution (20m) digital representation of Victoria's terrain surface.
		Structured in a regular array of pixels representing elevation, the DEM emphasises the measurement of height above a datum and the absolute elevation of the points contained in the model.
		When used together with other Vicmap Digital products and satellite imagery, the DEM can enhance many environmental and natural resource oriented applications such as terrain and trafficability analysis; land suitability and landscape sensitivity assessments; catchment hydrological modelling; modelling tree site condition, species distribution, biodiversity, or animal habitat suitability; and virtual reality simulation.
	www.land.vic.gov.au /land/lcnlc2.nsf/childdocs/-418EED712A81C5AE4A256A0A0015CDC1-F31E2DE1F7D75F504A256A4F0017DA3E-DA7CA8ABA02855EB4A256A50000DE72D-EE3CBEF231F1B6A7CA256E6200824F41-E93D83614DA95448CA256D660019CC8A?open (186 words)

	EO Newsroom: New Images - Cotopaxi Volcano, Ecuador
		Endeavour was mapping elevations on most of the Earth’s land surface during the Shuttle Radar Topography Mission (SRTM).
		The digital elevation model acquired by SRTM, with its resolution of 25 m x 25 m, is so rich in detail that you can even make out an inner crater with a diameter of 120 m by 250 m inside the outer crater (800 m x 650 m).
		Numerous valleys formed by powerful Lahars (mudflows) are prominent in the digital elevation model.
	earthobservatory.nasa.gov /Newsroom/NewImages/images.php3?img_id=5178 (274 words)

	TerraSource - A Terragen Resource Center - Copyright 2001-2004 by Timothy J. O'Donoghue
		Digital Terrain Modeling and Mapping Terrain Modeling and Mapping using DEM, SDTS, DRG, DLG and DTED Data.
		Digital Elevation Models of the Main Hawaiian Islands - Each island in one big file.
		Digital Elevation Models for the Main Eight Hawaiian Islands derived from USGS 7.5' Quads.
	www.terrasource.net (4282 words)

	USGS (U.S. Geological Survey) EROS, Sioux Falls, SD
		2) The National Elevation Dataset (NED) is the result of the maturation of the USGS effort to provide 1:24,000-scale Digital Elevation Model (DEM) data for the conterminous U.S. and 1:63,360-scale DEM data for Alaska in a seamless form.
		NED is the result of the maturation of the USGS effort to provide 1:24,000-scale Digital Elevation Model (DEM) data for the conterminous US and 1:63,360-scale DEM data for Alaska.
		The decision to provide SDTS DEMs through commercial vendors is consistent with the USGS goal of making more public domain data available at no charge while enabling the private sector to have a greater role in the distribution of USGS data.
	edc.usgs.gov /geodata (879 words)

	Encyclopedia: Digital elevation model (Site not responding. Last check: 2007-09-16)
		People who viewed "Digital elevation model" also viewed:
		A digital elevation model' (DEM) is a representation of the topography of the Earth in digital format, that is, by coordinates and numerical descriptions of altitude.
		Click for other authoritative sources for this topic (summarised at Factbites.com).
	www.nationmaster.com /encyclopedia/Digital-elevation-model (138 words)

	Radarsat Antarctic Mapping Project Digital Elevation Model Version 2 (Site not responding. Last check: 2007-09-16)
		The DEM incorporates topographic data from satellite radar altimetry, airborne radar surveys, the recently-updated Antarctic Digital Database (version 2), and large-scale topographic maps from the U.S. Geological Survey (USGS) and the Australian Antarctic Division.
		Although the RAMP DEM was created to aid in processing RAMP radar data, it does not utilize any RAMP radar data.
		The 1 km, 400 m, and 200 m DEM data are provided in ARC/INFO and binary grid formats, and the 1 km and 400 m DEMs are also available in ASCII format.
	www.nsidc.org /data/nsidc-0082.html (220 words)

	Elevation, haulover park - CATALOGUE OF DIGITAL ELEVATION DATA LAST UPDATED: 23-JAN-1997 (Site not responding. Last check: 2007-09-16)
		These maps are based on the 1 minute USGS digital elevation (DEM) database which Overlaid on the elevation map are data from the USGS DLG (Digital Line
		It includes details of elevation and bathymetric data, together with a section on available software for the display and manipulation of these data.
		Elevation data located on the degree lines (all four sides) correspond with the It is believed that this is the most accurate digital elevation data
	haulover-park.siteslinks.com /sil/haulover-park-elevation.htm (195 words)

	NGDC/WDC MGG, Boulder - 2 minute bathymetry/topography image selector
		This image was generated from digital data bases of seafloor and land elevations on a 2-minute latitude/longitude grid (1 minute of latitude = 1 nautical mile, or 1.852 km).
		Assumed illumination is from the west; shading is computed as a function of the east-west slope of the surface with a nonlinear exaggeration favoring low-relief areas.
		Land topography is from the GLOBE Project, an internationally designed, developed, and independently peer-reviewed global digital elevation model (DEM), at a latitude-longitude grid spacing of 30 arc-seconds (30").
	www.ngdc.noaa.gov /mgg/global/seltopo.html (736 words)

Try your search on: Qwika (all wikis)