Digital elevation model: Difference between revisions

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{{quotation|A '''digital elevation model''' (DEM) is a digital representation of ground surface topography or terrain. It is also widely known as a '''digital terrain model(DTM)'''. A DEM can be represented as a raster (a grid of squares) or as a triangular irregular network.}} ([http://en.wikipedia.org/wiki/Digital_terrain_model Wikipedia], retrieved 15:56, 12 May 2010 (UTC)).
== Introduction ==
 
{{quotation|A '''digital elevation model''' (DEM) is a digital representation of ground surface topography or terrain. It is also widely known as a '''digital terrain model(DTM)'''. A DEM can be represented as a raster (a grid of squares) or as a triangular irregular network.}} ([http://en.wikipedia.org/wiki/Digital_terrain_model Wikipedia], retrieved 17:39, 12 May 2010 (UTC)).
   
   
A '''digital surface model''' (DSM) on the other hand includes buildings, vegetation, and roads, as well as natural terrain features. The DEM provides a so-called bare-earth model, devoid of landscape features. While a DSM may be useful for landscape modeling, city modeling and visualization applications, a DEM is often required for flood or drainage modeling, land-use studies, geological applications, and much more. ([http://en.wikipedia.org/wiki/Digital_terrain_model Wikipedia], retrieved 15:56, 12 May 2010 (UTC)).
A '''digital surface model''' (DSM) on the other hand includes buildings, vegetation, and roads, as well as natural terrain features. The DEM provides a so-called bare-earth model, devoid of landscape features. While a DSM may be useful for landscape modeling, city modeling and visualization applications, a DEM is often required for flood or drainage modeling, land-use studies, geological applications, and much more. ([http://en.wikipedia.org/wiki/Digital_terrain_model Wikipedia], retrieved 17:39, 12 May 2010 (UTC)).
 
See also:
* [[3D printing of digital elevation models]] (various methods)
* [[Maperitive for laser cutting and 3D printing]] (using OpenStreetMap)
 
== Models and file Formats ==


== File Formats ==
-- This section badly needs revision and updating - [[User:Daniel K. Schneider|Daniel K. Schneider]] ([[User talk:Daniel K. Schneider|talk]]) 10:41, 21 March 2017 (CET)


Both digital elevation and surface models can either be represented as raster or vector graphics.
Both digital elevation and surface models can either be represented as raster or vector graphics.
Line 12: Line 20:
* Vector data either can be points (locations), lines or polylines (e.g. for topographics lines or roads), or polygons.  
* Vector data either can be points (locations), lines or polylines (e.g. for topographics lines or roads), or polygons.  


{{quotation|Additional non-spatial data can also be stored along with the spatial data represented by the coordinates of a vector geometry or the position of a raster cell. In vector data, the additional data contains attributes of the feature. For example, a forest inventory polygon may also have an identifier value and information about tree species. In raster data the cell value can store attribute information, but it can also be used as an identifier that can relate to records in another table.}} ([http://en.wikipedia.org/wiki/Geographic_information_system Wikipedia], retrieved 15:56, 12 May 2010 (UTC)).
{{quotation|Additional non-spatial data can also be stored along with the spatial data represented by the coordinates of a vector geometry or the position of a raster cell. In vector data, the additional data contains attributes of the feature. For example, a forest inventory polygon may also have an identifier value and information about tree species. In raster data the cell value can store attribute information, but it can also be used as an identifier that can relate to records in another table.}} ([http://en.wikipedia.org/wiki/Geographic_information_system Wikipedia], retrieved 17:39, 12 May 2010 (UTC)).
 
=== Digital elevation models ===


; Digital elevation models
;USGS DEM:
: {{quotation| The [http://en.wikipedia.org/wiki/USGS_DEM USGS DEM] standard is a geospatial file format developed by the United States Geological Survey for storing a raster-based digital elevation model. It is an open standard, and is used throughout the world. It has been superseded by the USGS's own SDTS format but the format remains popular due to large numbers of legacy files, self-containment, relatively simple field structure and broad, mature software support.}} (Wikipedia, retrieved 17:39, 12 May 2010 (UTC))


{{quotation| The [http://en.wikipedia.org/wiki/USGS_DEM USGS DEM] standard is a geospatial file format developed by the United States Geological Survey for storing a raster-based digital elevation model. It is an open standard, and is used throughout the world. It has been superseded by the USGS's own SDTS format but the format remains popular due to large numbers of legacy files, self-containment, relatively simple field structure and broad, mature software support.}} (Wikipedia, retrieved 15:56, 12 May 2010 (UTC))
; SDTS
{{quotation| The [http://mcmcweb.er.usgs.gov/sdts/ The Spatial Data Transfer Standard] (SDTS) is a robust way of transferring earth-referenced spatial data between dissimilar computer systems with the potential for no information loss. It is a transfer standard that embraces the philosophy of self-contained transfers, i.e. spatial data, attribute, georeferencing, data quality report, data dictionary, and other supporting metadata all included in the transfer.}} ([http://mcmcweb.er.usgs.gov/sdts/ USGS], retrieved 17:39, 12 May 2010 (UTC))


{{quotation| The [http://mcmcweb.er.usgs.gov/sdts/ The Spatial Data Transfer Standard] (SDTS) is a robust way of transferring earth-referenced spatial data between dissimilar computer systems with the potential for no information loss. It is a transfer standard that embraces the philosophy of self-contained transfers, i.e. spatial data, attribute, georeferencing, data quality report, data dictionary, and other supporting metadata all included in the transfer.}} ([http://mcmcweb.er.usgs.gov/sdts/ USGS], retrieved 15:56, 12 May 2010 (UTC))
; DTED
{{quotation|DTED (or Digital Terrain Elevation Data) is a standard of digital datasets which consists of a matrix of terrain elevation values. This standard was originally developed in the 1970s to support aircraft radar simulation and prediction.}} ([http://en.wikipedia.org/wiki/DTED DTED] (Wikipedia, retrieved 17:39, 12 May 2010 (UTC))


{{quotation|DTED (or Digital Terrain Elevation Data) is a standard of digital datasets which consists of a matrix of terrain elevation values. This standard was originally developed in the 1970s to support aircraft radar simulation and prediction.}} ([http://en.wikipedia.org/wiki/DTED DTED] (Wikipedia, retrieved 15:56, 12 May 2010 (UTC))
=== Other/combined models ===


; General puporse 3D formats
; SRTM
: {{quotation|The Shuttle Radar Topography Mission (SRTM) is a partnership between NASA and the National Geospatial-Intelligence Agency (NGA). Flown aboard the NASA Space Shuttle Endeavour (11-22 February 2000), SRTM fulfilled its mission to map the world in three dimensions.}} ([http://eros.usgs.gov/ EORS.usgs.gov])


* See [[3D File Format]]s
; Advanced Spaceborne Thermal Emission and Reflection Radiometer
 
* [http://en.wikipedia.org/wiki/Advanced_Spaceborne_Thermal_Emission_and_Reflection_Radiometer Advanced Spaceborne Thermal Emission and Reflection Radiometer]. {{quotation|ASTER provides high-resolution images of the Earth in 15 different bands of the electromagnetic spectrum, ranging from visible to thermal infrared light. The resolution of images ranges between 15 to 90 meters. ASTER data are used to create detailed maps of surface temperature of land, emissivity, reflectance, and elevation.}} (http://en.wikipedia.org/wiki/Advanced_Spaceborne_Thermal_Emission_and_Reflection_Radiometer[ Wikipedia], retrieved 17:39, 12 May 2010 (UTC))
 
=== General pupose 3D formats ===
 
* See [[3D file format]]s


== Available terrain maps ==
== Available terrain maps ==


; STRM
[http://www2.jpl.nasa.gov/srtm/ The Shuttle Radar Topography Mission (SRTM)] Maps.


; GTOPS30
Download links:
* [http://dds.cr.usgs.gov/srtm/ directory]. Read [http://dds.cr.usgs.gov/srtm/What_are_these.pdf What_are_these.pdf] first. Can be imported to ARCInfo with a little work (not tested)


[http://eros.usgs.gov/#/Find_Data/Products_and_Data_Available/gtopo30_info GTOPO30] is is a global digital elevation model (DEM) with a horizontal grid spacing of 30 arc seconds (approximately 1 kilometer). GTOPO30 was derived from several raster and vector sources of topographic information.
; GTOPO30


; Download links
[http://eros.usgs.gov/#/Find_Data/Products_and_Data_Available/gtopo30_info GTOPO30] is a global digital elevation model (DEM) of the whole world with a horizontal grid spacing of 30 arc seconds (approximately 1 kilometer). GTOPO30 was derived from several raster and vector sources of topographic information.


* [http://edcdaac.usgs.gov/gtopo30/gtopo30.html GTOPO30 Homepage]
* [http://en.wikipedia.org/wiki/GTOPO30 GTOPO30] (Wikipedia)
 
Download links:
* [http://eros.usgs.gov/#/Find_Data/Products_and_Data_Available/gtopo30_info GTOPO30] (US Geological survey EROS Data Center)
* [ftp://edcftp.cr.usgs.gov/pub/data/gtopo30/global/ GTOPO30 FTP Server]
* [ftp://edcftp.cr.usgs.gov/pub/data/gtopo30/global/ GTOPO30 FTP Server]
[http://en.wikipedia.org/wiki/Advanced_Spaceborne_Thermal_Emission_and_Reflection_Radiometer Advanced Spaceborne Thermal Emission and Reflection Radiometer]
* [http://eros.usgs.gov/#/Find_Data/Products_and_Data_Available/gtopo30/README Documentation about the formats]
 
; Other
* [http://www.viewfinderpanoramas.org/ Viewfinder Panoramas] (many selected area tiles of the world)


== Links ==
== Links ==
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* [http://en.wikipedia.org/wiki/Comparison_of_web_map_services Web Map Services]
* [http://en.wikipedia.org/wiki/Comparison_of_web_map_services Web Map Services]
* [http://www.maps-for-free.com Maps-For-Free.com]. Allows to display various Layers on either satellite, terrain, relief or OSM view. Allows to take a picture (jpg).
* [http://www.maps-for-free.com Maps-For-Free.com]. Allows to display various Layers on either satellite, terrain, relief or OSM view. Allows to take a picture (jpg).
* [https://lpdaac.usgs.gov/lpdaac/get_data/glovis GloVis] (USGS Global Visualization) is an online search and order tool for selected satellite data. It includes
* [https://lpdaac.usgs.gov/lpdaac/get_data/wist WIST] (Warehouse Inventory Search Tool) is a web-based client to search and order earth science data from various NASA and affiliated centers, e.g. GloVis.
* [https://lpdaac.usgs.gov/lpdaac/get_data/mrtweb MRTWeb] combines familiar capabilities of the USGS Global Visualization Viewer (GloVis) and the downloadable MODIS Reprojection Tool (MRT)
=== Software ===
; Viewing
* [http://en.wikipedia.org/wiki/TerraLook TerraLook] (Wikipedia) a free satellite image viewing tool, developed by Sujoy Chaudhuri of Ecollage, India.
* [http://en.wikipedia.org/wiki/Google_Earth Google Earth] (Wikipedia)
; Multipurpose
* [http://en.wikipedia.org/wiki/ArcGIS_Desktop ArcGIS] (Wikipedia) Commercial group of geographic information system (GIS) software products produced by ESRI.
=== Other kinds of 3D representations of 2D pictures ===
* [https://www.thingiverse.com/thing:74322 Customizable Lithopane] (but followup other projects referred to)


=== To sort out ===
=== To sort out ===
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* [http://en.wikipedia.org/wiki/NASA_World_Wind NASA World Wind]
* [http://en.wikipedia.org/wiki/NASA_World_Wind NASA World Wind]


* [http://en.wikipedia.org/wiki/GTOPO30 GTOPO30] (Wikipedia)
== Bibliography, links and footnotes ==
 
=== Printing with a RepRap printer ===
(e.g. a [[RapMan]])


* [http://www.bitsfrombytes.com/wiki/index.php?title=Geography_-_3D_Terrain Geography - 3D Terrain] crosscurricular projects by David White
<references/>


[[Category:3D]]
[[Category:3D]]
[[Category:RapMan]]
[[Category:Cartography]]
[[Category:Cartography]]

Latest revision as of 14:34, 18 January 2018

Draft

Introduction

“A digital elevation model (DEM) is a digital representation of ground surface topography or terrain. It is also widely known as a digital terrain model(DTM). A DEM can be represented as a raster (a grid of squares) or as a triangular irregular network.” (Wikipedia, retrieved 17:39, 12 May 2010 (UTC)).

A digital surface model (DSM) on the other hand includes buildings, vegetation, and roads, as well as natural terrain features. The DEM provides a so-called bare-earth model, devoid of landscape features. While a DSM may be useful for landscape modeling, city modeling and visualization applications, a DEM is often required for flood or drainage modeling, land-use studies, geological applications, and much more. (Wikipedia, retrieved 17:39, 12 May 2010 (UTC)).

See also:

Models and file Formats

-- This section badly needs revision and updating - Daniel K. Schneider (talk) 10:41, 21 March 2017 (CET)

Both digital elevation and surface models can either be represented as raster or vector graphics.

  • Raster data can present either just images (as in any image format like *.jpg*) or include specific data about a cell.
  • Vector data either can be points (locations), lines or polylines (e.g. for topographics lines or roads), or polygons.

“Additional non-spatial data can also be stored along with the spatial data represented by the coordinates of a vector geometry or the position of a raster cell. In vector data, the additional data contains attributes of the feature. For example, a forest inventory polygon may also have an identifier value and information about tree species. In raster data the cell value can store attribute information, but it can also be used as an identifier that can relate to records in another table.” (Wikipedia, retrieved 17:39, 12 May 2010 (UTC)).

Digital elevation models

USGS DEM
“The USGS DEM standard is a geospatial file format developed by the United States Geological Survey for storing a raster-based digital elevation model. It is an open standard, and is used throughout the world. It has been superseded by the USGS's own SDTS format but the format remains popular due to large numbers of legacy files, self-containment, relatively simple field structure and broad, mature software support.” (Wikipedia, retrieved 17:39, 12 May 2010 (UTC))
SDTS

“The The Spatial Data Transfer Standard (SDTS) is a robust way of transferring earth-referenced spatial data between dissimilar computer systems with the potential for no information loss. It is a transfer standard that embraces the philosophy of self-contained transfers, i.e. spatial data, attribute, georeferencing, data quality report, data dictionary, and other supporting metadata all included in the transfer.” (USGS, retrieved 17:39, 12 May 2010 (UTC))

DTED

“DTED (or Digital Terrain Elevation Data) is a standard of digital datasets which consists of a matrix of terrain elevation values. This standard was originally developed in the 1970s to support aircraft radar simulation and prediction.” (DTED (Wikipedia, retrieved 17:39, 12 May 2010 (UTC))

Other/combined models

SRTM
“The Shuttle Radar Topography Mission (SRTM) is a partnership between NASA and the National Geospatial-Intelligence Agency (NGA). Flown aboard the NASA Space Shuttle Endeavour (11-22 February 2000), SRTM fulfilled its mission to map the world in three dimensions.” (EORS.usgs.gov)
Advanced Spaceborne Thermal Emission and Reflection Radiometer

General pupose 3D formats

Available terrain maps

STRM

The Shuttle Radar Topography Mission (SRTM) Maps.

Download links:

GTOPO30

GTOPO30 is a global digital elevation model (DEM) of the whole world with a horizontal grid spacing of 30 arc seconds (approximately 1 kilometer). GTOPO30 was derived from several raster and vector sources of topographic information.

Download links:

Other

Links

Overviews

Visualization and GIS

(these are related subjects)

Overviews and indexes of File formats

Actors

Online maps to look at

(some can show relief).

  • Maps-For-Free.com. Allows to display various Layers on either satellite, terrain, relief or OSM view. Allows to take a picture (jpg).
  • GloVis (USGS Global Visualization) is an online search and order tool for selected satellite data. It includes
  • WIST (Warehouse Inventory Search Tool) is a web-based client to search and order earth science data from various NASA and affiliated centers, e.g. GloVis.
  • MRTWeb combines familiar capabilities of the USGS Global Visualization Viewer (GloVis) and the downloadable MODIS Reprojection Tool (MRT)

Software

Viewing
  • TerraLook (Wikipedia) a free satellite image viewing tool, developed by Sujoy Chaudhuri of Ecollage, India.
  • Google Earth (Wikipedia)
Multipurpose
  • ArcGIS (Wikipedia) Commercial group of geographic information system (GIS) software products produced by ESRI.

Other kinds of 3D representations of 2D pictures

To sort out

Bibliography, links and footnotes

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