Difference between revisions of "Projection"

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= Projections and Datum Transformations =
 
= Projections and Datum Transformations =
  
PRJ files (in the usual WKT format) as used by recent versions of ESRI ArcView
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== Brief introduction to projections and spatial transformations in GRASS ==
http://esri-germany.de/downloads/software/Koordinatensysteme.zip
 
  
http://support.esri-germany.de/files/support/KoordinatensystemeInDeutschland.pdf
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A GRASS location is referenced with a single projection and coordinate system (or unreferenced as XY location). When creating a new location from an existing raster or vector map using the tools available from the startup screen or the map import commands, projection and coordinate system are defined. To change the projection of maps, a new location has to be created and the desired maps have to be reprojected into it from the source location as explained below.  
http://support.esri-germany.de/files/support/KoordinatensystemeNachbarnDeutschlands.pdf
 
http://support.esri-germany.de/files/support/KoordinatensystemeWeltweit.pdf
 
  
http://www.epsg.org/Geodetic.html
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Read on in {{cmd|projectionintro}}...
  
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== Creation of a GRASS location ==
  
http://www.alectoria.at/content/view/17/1/
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* for the concept, see [[Location and Mapsets]]
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* for creating a location, see [[GRASS Location Wizard]]
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* Reprojection, see [[Map Reprojection]]
  
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= Support Material =
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* Vector data: have enough vertices in your vector data: [[File:V proj result.png|300px|center|thumb|Results in EU LAEA (EPSG: 3035)]]
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* Ready to use .PRJ files (in the usual WKT format) as used by recent versions of ESRI ArcView: [http://esri-germany.de/downloads/software/Koordinatensysteme.zip download]
  
== Headline text ==
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= See also =
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View Map Projections
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* http://map-projections.net/singleview.php
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* [http://www.progonos.com/furuti/MapProj/Normal/TOC/cartTOC.html Cartographical Map Projections] by Carlos A. Furuti
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Lists
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* [http://www.epsg-registry.org/ EPSG Dataset]
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* [https://www.asprs.org/asprs-publications/grids-and-datums ASPRS Grids and Datum]
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* [http://geotiff.maptools.org/proj_list/ Projections Transform List (PROJ4)]
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* [http://www.mapref.org/ MapRef - The Collection of Map Projections and Reference Systems for Europe]
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* [http://www.crs-geo.eu Information and Service System for European Coordinate Reference Systems - CRS]
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Related to Germany:
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* http://support.esri-germany.de/files/support/KoordinatensystemeInDeutschland.pdf
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* http://support.esri-germany.de/files/support/KoordinatensystemeNachbarnDeutschlands.pdf
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* http://support.esri-germany.de/files/support/KoordinatensystemeWeltweit.pdf
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Related to Austria:
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* [http://www.alectoria.at/content/view/17/1/ Projection parameters of Austria]
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== Google Map Projection ==
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Also called "pseudo-mercator" - note that there are many issues with this projection! Handle with care.
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* http://www.sharpgis.net/2007/07/27/TheMicrosoftLiveMapsAndGoogleMapsProjection.aspx
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* http://cfis.savagexi.com/articles/2006/05/03/google-maps-deconstructed
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[[Category: FAQ]]

Latest revision as of 09:37, 30 December 2019

Projections and Datum Transformations

Brief introduction to projections and spatial transformations in GRASS

A GRASS location is referenced with a single projection and coordinate system (or unreferenced as XY location). When creating a new location from an existing raster or vector map using the tools available from the startup screen or the map import commands, projection and coordinate system are defined. To change the projection of maps, a new location has to be created and the desired maps have to be reprojected into it from the source location as explained below.

Read on in projectionintro...

Creation of a GRASS location

Support Material

  • Vector data: have enough vertices in your vector data:
    Results in EU LAEA (EPSG: 3035)
  • Ready to use .PRJ files (in the usual WKT format) as used by recent versions of ESRI ArcView: download

See also

View Map Projections

Lists

Related to Germany:

Related to Austria:

Google Map Projection

Also called "pseudo-mercator" - note that there are many issues with this projection! Handle with care.