GIS Concepts - Revision history

Ltb25: /* Background material */

2025-06-24T23:06:54Z

Background material

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	=== Background material ===		=== Background material ===

	* [http://oceanservice.noaa.gov/education/kits/geodesy/welcome.html An introduction to Geodesy] from NOAA		* [http://oceanservice.noaa.gov/education/kits/geodesy/welcome.html An introduction to Geodesy] from NOAA (currently unavailable)
	* [http://en.wikipedia.org/wiki/Geodesy Wikipedia's Geodesy entry]		* [http://en.wikipedia.org/wiki/Geodesy Wikipedia's Geodesy entry]
	* [http://en.wikipedia.org/wiki/GIS Wikipedia's GIS entry]		* [http://en.wikipedia.org/wiki/GIS Wikipedia's GIS entry]

Neteler: URLs updated

2019-12-30T16:19:03Z

URLs updated

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	* [http://earth-info.nima.mil/GandG/publications/ NGA Geodesy and Geophysics publications]		* [http://earth-info.nima.mil/GandG/publications/ NGA Geodesy and Geophysics publications]
	* [http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/guidecontents/index.html UK Ordnance Survey primer on coordinate system concepts] ([http://www.ordnancesurvey.co.uk/gps/docs/A_Guide_to_Coordinate_Systems_in_Great_Britain.pdf PDF])		* [http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/guidecontents/index.html UK Ordnance Survey primer on coordinate system concepts] ([http://www.ordnancesurvey.co.uk/gps/docs/A_Guide_to_Coordinate_Systems_in_Great_Britain.pdf PDF])
	* Clifford J Mugnier's [~~http~~://www.asprs.org/~~resources~~/grids/ Grids and Datums column from PE&RS] containing detailed descriptions of many national projections & datums		* Clifford J Mugnier's [https://www.asprs.org/asprs-publications/grids-and-datums Grids and Datums column from PE&RS] containing detailed descriptions of many national projections & datums

	=== Map projections ===		=== Map projections ===
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	Setting a datum is optional, but highly recommended.		Setting a datum is optional, but highly recommended.

	GRASS uses ~~a modified version of~~ the [~~http~~://proj~~.maptools~~.org PROJ.4] library.		GRASS uses the [https://proj.org PROJ] library.

	=== Modules controling a location's map projection ===		=== Modules controling a location's map projection ===
	* ~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~g.proj~~.html g.proj] help page~~		* {{cmd\|g.proj}} help page
	* [http://grass.osgeo.org/grass64/manuals/html64_user/g.setproj.html g.setproj] help page

	=== Modules for reprojecting GIS maps and data ===		=== Modules for reprojecting GIS maps and data ===

	* ~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~r.proj~~.html r.proj]~~ for reprojecting raster maps		* {{cmd\|r.proj}} for reprojecting raster maps
	* ~~[http://grass.osgeo.org/grass64/manuals/html64_user/v.proj.html~~ v.proj] for reprojecting vector maps		* {{cmd\|v.proj}} for reprojecting vector maps
	* ~~[http://grass.osgeo.org/grass64/manuals/html64_user/m.proj.html~~ m.proj] for reprojecting a list of coordinate pairs		* {{cmd\|m.proj}} for reprojecting a list of coordinate pairs

	=== Modules for georectifying images ===		=== Modules for georectifying images ===

	* ~~[http://grass.osgeo.org/grass64/manuals/html64_user/r.region.html~~ r.region] for resetting a raster map's bounds information		* {{cmd\|r.region}} for resetting a raster map's bounds information
	* gis.m GIS manager GeoReferencing tool (File menu)		* gis.m GIS manager GeoReferencing tool (File menu)
	* ~~[http://grass.osgeo.org/grass64/manuals/html64_user/i.points.html~~ i.points] and ~~[http://grass.osgeo.org/grass64/manuals/html64_user/i.vpoints.html~~ i.vpoints] for setting GCPs		* {{cmd\|i.points}} and {{cmd\|i.vpoints}} for setting GCPs
	* ~~[http://grass.osgeo.org/grass64/manuals/html64_user/i.rectify.html~~ i.rectify] for georectifying imagery		* {{cmd\|i.rectify}} for georectifying imagery
	* [http://www.gdal.org ~~GDALwarp~~] (use with gdal_translate, see the i.warp script in the wiki [[GRASS_AddOns#Imagery_add-ons\|AddOns]] page)		* [http://www.gdal.org gdalwarp] (use with gdal_translate, see the i.warp script in the wiki [[GRASS_AddOns#Imagery_add-ons\|AddOns]] page)

	;[[Georeferencing]]		;[[Georeferencing]]
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	Region settings determine the spatial extent and resolution of the grid.		Region settings determine the spatial extent and resolution of the grid.

	;~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~rasterintro~~.html Raster Intro]~~		;{{cmd\|rasterintro}}

	[[GRASS Raster Mask]]		[[GRASS Raster Mask]]
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	A stack of 2D raster maps.		A stack of 2D raster maps.

	;~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~raster3dintro~~.html Raster 3D Intro]~~		;{{cmd\|raster3dintro}}

	===Vector Data===		===Vector Data===
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	Data which occurs as a series of coordinates. e.g. a GPS position or coastline map. May be a point, line, area, etc in either 2D or 3D space. Generally independent of region settings.		Data which occurs as a series of coordinates. e.g. a GPS position or coastline map. May be a point, line, area, etc in either 2D or 3D space. Generally independent of region settings.

	;~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~vectorintro~~.html Vector Intro]~~		;{{cmd\|vectorintro}}
	[[Vectordata]]		[[Vectordata]]

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	As far as the GIS is concerned this is just another raster map, but there are several modules specially tailored for rectification and processing common imagery types. e.g. ortho-photos or multi-channel [[LANDSAT]] data.		As far as the GIS is concerned this is just another raster map, but there are several modules specially tailored for rectification and processing common imagery types. e.g. ortho-photos or multi-channel [[LANDSAT]] data.

	* ~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~imageryintro~~.html GRASS Imagery module introduction]~~		* {{cmd\|imageryintro}}

	* The GRASS [[Image processing]] wiki page		* The GRASS [[Image processing]] wiki page

	===Site Data===		=== Old GRASS GIS 5 / 6 Site Data===
	Old versions of GRASS (5 and earlier) treated point data separate to line and polygon data. GRASS 6 classes all vector data features the same. Convert old sites file data into GRASS 6 vector format with the GRASS 6 ~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~v.in.sites~~.html v.in.sites]~~ or		Old versions of GRASS (5 and earlier) treated point data separate to line and polygon data. GRASS 6 classes all vector data features the same. Convert old sites file data into GRASS 6 vector format with the GRASS 6 {{cmd\|v.in.sites}} or
	~~[http://grass.osgeo.org/grass64/manuals/html64_user/v.in.sites.all.html~~ v.in.sites.all] modules.		{{cmd\|v.in.sites.all}} modules.

	==Conversions between data types==		==Conversions between data types==
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	{\| border="1"		{\| border="1"
	\| From / To		\| From / To
	!~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~rasterintro~~.html Raster]~~		!{{cmd\|rasterintro}}
	!~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~raster3dintro~~.html 3D Raster]~~		!{{cmd\|raster3dintro}}
	!~~[http://grass.osgeo.org/grass64/manuals/html64_user/~~vectorintro~~.html Vector]~~		!{{cmd\|vectorintro}}
	\|-		\|-
	! Raster		! Raster
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	There is always a PERMANENT mapset which is readable from all other mapsets within the same location. Read access to maps in other mapsets is managed with the 'g.mapsets' command or by adding the "@" symbol and mapset name (e.g. <tt>map@othermapset</tt>).		There is always a PERMANENT mapset which is readable from all other mapsets within the same location. Read access to maps in other mapsets is managed with the 'g.mapsets' command or by adding the "@" symbol and mapset name (e.g. <tt>map@othermapset</tt>).



	==Raster GIS Analysis==		==Raster GIS Analysis==

Neteler at 09:53, 27 September 2019

2019-09-27T09:53:07Z

← Older revision		Revision as of 09:53, 27 September 2019
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	[[Category:Community]]		[[Category:Community]]
			[[Category:Raster]]
			[[Category:Vector]]

Neteler: + Vertical datum files

2014-02-15T17:14:57Z

+ Vertical datum files

← Older revision		Revision as of 17:14, 15 February 2014
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	: (besides the web page have a look at the PDF fact sheet and guide linked therein)		: (besides the web page have a look at the PDF fact sheet and guide linked therein)
	<!-- old (better?>) link: http://web.archive.org/web/20070828042606/http://www.linz.govt.nz/core/surveysystem/geodeticinfo/geodeticdatums/nzgd49tonzgd2000/index.html -->		<!-- old (better?>) link: http://web.archive.org/web/20070828042606/http://www.linz.govt.nz/core/surveysystem/geodeticinfo/geodeticdatums/nzgd49tonzgd2000/index.html -->
			* Vertical datum files: http://download.osgeo.org/proj/vdatum/

	==How GRASS deals with geodetics==		==How GRASS deals with geodetics==

⚠️MilenaN: Reverted edits by Reverse22 (talk) to last revision by Landa

2011-12-30T21:37:14Z

Reverted edits by Reverse22 (talk) to last revision by Landa

← Older revision		Revision as of 21:37, 30 December 2011
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	[[Category:Community]]		[[Category:Community]]


	~~==Other==~~
	~~[http://thetvtopc.com/Reverse_Cell_Phone_Lookup_Number reverse phone lookup]~~

⚠️Reverse22 at 20:50, 30 December 2011

2011-12-30T20:50:15Z

← Older revision		Revision as of 20:50, 30 December 2011
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	[[Category:Community]]		[[Category:Community]]


			==Other==
			[http://thetvtopc.com/Reverse_Cell_Phone_Lookup_Number reverse phone lookup]

⚠️Landa: /* Simple Raster Math */

2011-01-13T14:00:31Z

Simple Raster Math

← Older revision		Revision as of 14:00, 13 January 2011
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	GRASS comes bundled with the {{cmd\|r.mapcalc}} command line tool as well as a GUI interface for the tool accessible using the {{cmd\|r.mapcalculator}} command. This GUI allows the user to easily assign raster maps to the variables used in the formulas and easily create mathematical strings that will result in a new raster data set containing the results.		GRASS comes bundled with the {{cmd\|r.mapcalc}} command line tool as well as a GUI interface for the tool accessible using the {{cmd\|r.mapcalculator}} command. This GUI allows the user to easily assign raster maps to the variables used in the formulas and easily create mathematical strings that will result in a new raster data set containing the results.

	~~[[Category:Development]]~~
	[[Category:Community]]		[[Category:Community]]

⚠️HamishBowman: /* Raster Data */ rm dev stuff

2009-08-26T07:43:09Z

Raster Data: rm dev stuff

← Older revision		Revision as of 07:43, 26 August 2009
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	;[http://grass.osgeo.org/grass64/manuals/html64_user/rasterintro.html Raster Intro]		;[http://grass.osgeo.org/grass64/manuals/html64_user/rasterintro.html Raster Intro]
	~~[[Replacement raster format]]~~

	[[GRASS Raster Mask]]		[[GRASS Raster Mask]]

⚠️HamishBowman: dupe :)

2009-06-11T12:34:50Z

dupe :)

← Older revision		Revision as of 12:34, 11 June 2009
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	* [http://earth-info.nima.mil/GandG/publications/ NGA Geodesy and Geophysics publications]		* [http://earth-info.nima.mil/GandG/publications/ NGA Geodesy and Geophysics publications]
	* [http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/guidecontents/index.html UK Ordnance Survey primer on coordinate system concepts] ([http://www.ordnancesurvey.co.uk/gps/docs/A_Guide_to_Coordinate_Systems_in_Great_Britain.pdf PDF])		* [http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/guidecontents/index.html UK Ordnance Survey primer on coordinate system concepts] ([http://www.ordnancesurvey.co.uk/gps/docs/A_Guide_to_Coordinate_Systems_in_Great_Britain.pdf PDF])
	* Clifford J Mugnier's [http://www.asprs.org/resources/grids/ Grids and Datums column from PE&RS]~~, which now has articles covering~~ many ~~countries.~~		* Clifford J Mugnier's [http://www.asprs.org/resources/grids/ Grids and Datums column from PE&RS] containing detailed descriptions of many national projections & datums

	=== Map projections ===		=== Map projections ===

	* [http://www.asprs.org/resources/grids/ ASPRS Grids and Datums]: detailed descriptions of national projections
	* [http://www.mapref.org/ MapRef] - The Collection of Map Projections and Reference Systems for Europe		* [http://www.mapref.org/ MapRef] - The Collection of Map Projections and Reference Systems for Europe
	* [http://www.remotesensing.org/geotiff/proj_list/ Projections Transform Lists] (PROJ4)		* [http://www.remotesensing.org/geotiff/proj_list/ Projections Transform Lists] (PROJ4)

⚠️HamishBowman: /* Background material */ cliff's notes

2009-06-11T12:32:45Z

Background material: cliff's notes

← Older revision		Revision as of 12:32, 11 June 2009
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	* [http://earth-info.nima.mil/GandG/publications/ NGA Geodesy and Geophysics publications]		* [http://earth-info.nima.mil/GandG/publications/ NGA Geodesy and Geophysics publications]
	* [http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/guidecontents/index.html UK Ordnance Survey primer on coordinate system concepts] ([http://www.ordnancesurvey.co.uk/gps/docs/A_Guide_to_Coordinate_Systems_in_Great_Britain.pdf PDF])		* [http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/guidecontents/index.html UK Ordnance Survey primer on coordinate system concepts] ([http://www.ordnancesurvey.co.uk/gps/docs/A_Guide_to_Coordinate_Systems_in_Great_Britain.pdf PDF])
			* Clifford J Mugnier's [http://www.asprs.org/resources/grids/ Grids and Datums column from PE&RS], which now has articles covering many countries.

	=== Map projections ===		=== Map projections ===