Gis Concepts/id - Revision history

⚠️Firmanhadi: /* Modules controling a location's map projection */

2008-11-12T05:42:29Z

Modules controling a location's map projection

← Older revision		Revision as of 05:42, 12 November 2008
Line 44:		Line 44:
	GRASS menggunakan pustaka [http://proj.maptools.org PROJ.4] yang telah dimodifikasi.		GRASS menggunakan pustaka [http://proj.maptools.org PROJ.4] yang telah dimodifikasi.

	=== ~~Modules controling a~~ location~~'s map projection~~ ===		=== Modul yang mengatur proyeksi peta dari sebuah location ===
	* [http://grass.osgeo.org/grass64/manuals/html64_user/g.proj.html g.proj] ~~help page~~		* Halaman bantuan [http://grass.osgeo.org/grass64/manuals/html64_user/g.proj.html g.proj]
	* [http://grass.osgeo.org/grass64/manuals/html64_user/g.setproj.html g.setproj] ~~help page~~		* Halaman bantuan [http://grass.osgeo.org/grass64/manuals/html64_user/g.setproj.html g.setproj]

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

⚠️Firmanhadi: /* Bagaimana GRASS menangani hal-hal yang terkait dengan geodetik */

2008-11-12T05:40:50Z

Bagaimana GRASS menangani hal-hal yang terkait dengan geodetik

← Older revision		Revision as of 05:40, 12 November 2008
Line 37:		Line 37:
	==Bagaimana GRASS menangani hal-hal yang terkait dengan geodetik==		==Bagaimana GRASS menangani hal-hal yang terkait dengan geodetik==

	Dalam GRASS, sebuah ellipsoid dan ~~sebuah~~ spheroid adalah hal yang sama, dan ellipsoid adalah istilah yang cenderung digunakan.		Dalam GRASS, sebuah ellipsoid dan spheroid adalah hal yang sama, dan ellipsoid adalah istilah yang cenderung digunakan.

	~~As far as~~ GRASS ~~is concerned~~, a datum ~~is made up of an~~ ellipsoid ~~and an origin~~.		Dalam GRASS, sebuah datum dibentuk dari ellipsoid dan titik sumbu.
	~~Setting a~~ datum ~~is optional~~, ~~but highly recommended~~.		Pengaturan datum bersifat opsional, tetapi amat disarankan.

	GRASS ~~uses a modified version of the~~ [http://proj.maptools.org PROJ.4] ~~library~~.		GRASS menggunakan pustaka [http://proj.maptools.org PROJ.4] yang telah dimodifikasi.

	=== Modules controling a location's map projection ===		=== Modules controling a location's map projection ===

⚠️Firmanhadi: /* How GRASS deals with geodetics */

2008-09-30T16:14:23Z

How GRASS deals with geodetics

← Older revision		Revision as of 16:14, 30 September 2008
Line 35:		Line 35:
	<!-- 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 -->

	==~~How~~ GRASS ~~deals with geodetics~~==		==Bagaimana GRASS menangani hal-hal yang terkait dengan geodetik==

	~~As far as~~ GRASS ~~is concerned~~, an ellipsoid ~~and a~~ spheroid ~~are the same thing~~, ~~and~~ ellipsoid ~~is the prefered name~~.		Dalam GRASS, sebuah ellipsoid dan sebuah spheroid adalah hal yang sama, dan ellipsoid adalah istilah yang cenderung digunakan.

	As far as GRASS is concerned, a datum is made up of an ellipsoid and an origin.		As far as GRASS is concerned, a datum is made up of an ellipsoid and an origin.

⚠️Firmanhadi: /* Datum peta */

2008-09-30T15:46:03Z

Datum peta

← Older revision		Revision as of 15:46, 30 September 2008
Line 32:		Line 32:
	* [http://home.online.no/~sigurdhu/WGS84_Eng.html Bagaimana WGS 84 mendefinisikan Bumi]		* [http://home.online.no/~sigurdhu/WGS84_Eng.html Bagaimana WGS 84 mendefinisikan Bumi]
	* Sebuah diskusi tentang [http://www.linz.govt.nz/core/surveysystem/geodeticinfo/conversions/datums/nzgd1949-nzgd2000/index.html transformasi datum grid 3-term, 7-term dan NTv2] oleh Land Information New Zealand		* Sebuah diskusi tentang [http://www.linz.govt.nz/core/surveysystem/geodeticinfo/conversions/datums/nzgd1949-nzgd2000/index.html transformasi datum grid 3-term, 7-term dan NTv2] oleh Land Information New Zealand
	: (~~besides the web page have a look at the PDF~~ fact sheet ~~and guide linked therein~~)		: (selain isi halaman webnya, silakan lihat juga fact sheet PDF dan panduan yang ada di dalamnya)
	<!-- 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 -->

⚠️Firmanhadi: /* Datum peta */

2008-09-30T15:44:50Z

Datum peta

← Older revision		Revision as of 15:44, 30 September 2008
Line 31:		Line 31:
	* [http://www.colorado.edu/geography/gcraft/notes/datum/datum.html Pengantar tentang datum geodetik] oleh Peter Dana		* [http://www.colorado.edu/geography/gcraft/notes/datum/datum.html Pengantar tentang datum geodetik] oleh Peter Dana
	* [http://home.online.no/~sigurdhu/WGS84_Eng.html Bagaimana WGS 84 mendefinisikan Bumi]		* [http://home.online.no/~sigurdhu/WGS84_Eng.html Bagaimana WGS 84 mendefinisikan Bumi]
	* ~~A discussion of~~ [http://www.linz.govt.nz/core/surveysystem/geodeticinfo/conversions/datums/nzgd1949-nzgd2000/index.html 3-term, 7-term, dan NTv2 ~~transformasi datum grid~~] oleh Land Information New Zealand		* Sebuah diskusi tentang [http://www.linz.govt.nz/core/surveysystem/geodeticinfo/conversions/datums/nzgd1949-nzgd2000/index.html transformasi datum grid 3-term, 7-term dan NTv2] oleh Land Information New Zealand
	: (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 -->

⚠️Firmanhadi: /* Geodesy and Cartography */

2008-09-30T15:43:28Z

Geodesy and Cartography

← Older revision		Revision as of 15:43, 30 September 2008
Line 1:		Line 1:
	{{Trans\|Bahasa Indonesia}}		{{Trans\|Bahasa Indonesia}}

	== ~~Geodesy and Cartography~~ ==		== Geodesi dan Kartografi ==
	=== ~~Background material~~ ===		=== Bahan pengantar ===

	* [http://oceanservice.noaa.gov/education/kits/geodesy/welcome.html ~~An introduction to Geodesy~~] ~~from~~ NOAA		* [http://oceanservice.noaa.gov/education/kits/geodesy/welcome.html Pendahuluan tentang Geodesi] dari NOAA
	* [http://en.wikipedia.org/wiki/Geodesy Wikipedia~~'s Geodesy entry~~]		* [http://en.wikipedia.org/wiki/Geodesy Literatur tentang Geodesi dari Wikipedia]
	* [http://en.wikipedia.org/wiki/GIS Wikipedia~~'s GIS entry~~]		* [http://en.wikipedia.org/wiki/GIS Literatur tentang GIS dari Wikipedia]
	* [http://earth-info.nima.mil/GandG/publications/ NGA ~~Geodesy and Geophysics publications~~]		* [http://earth-info.nima.mil/GandG/publications/ Publikasi tentang Geodesi dan Geofisik dari NGA]
	* [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 tentang konsep sistem koordinat] ([http://www.ordnancesurvey.co.uk/gps/docs/A_Guide_to_Coordinate_Systems_in_Great_Britain.pdf PDF])

	=== ~~Map projections~~ ===		=== Proyeksi peta ===

	* [http://www.asprs.org/resources/grids/ ASPRS ~~Grids and Datums~~]: ~~detailed descriptions of national projections~~		* [http://www.asprs.org/resources/grids/ ASPRS Grid dan Datum]: deskripsi detil tentang proyeksi nasional
	* [http://www.mapref.org/ MapRef] - ~~The Collection of Map Projections and Reference Systems for Europe~~		* [http://www.mapref.org/ MapRef] - Koleksi Proyeksi Peta dan Sistem Referensi untuk Eropa
	* [http://www.remotesensing.org/geotiff/proj_list/ ~~Projections Transform Lists~~] (PROJ4)		* [http://www.remotesensing.org/geotiff/proj_list/ Daftar Transformasi Proyeksi] (PROJ4)
	* [http://www.dmap.co.uk/utmworld.htm UTM ~~Zones~~]		* [http://www.dmap.co.uk/utmworld.htm Zone UTM]

	EPSG:		EPSG:
	* [http://www.epsg.org EPSG ~~projection codes~~]		* [http://www.epsg.org Kode proyeksi EPSG]
	: [http://www.epsg-registry.org/ EPSG ~~database search~~]		: [http://www.epsg-registry.org/ Pencarian basisdata EPSG]
	: [http://spatialreference.org/ Spatialreference ~~community portal~~]		: [http://spatialreference.org/ Portal komunitas Spatialreference]

	~~Projection galleries~~:		Galeri Proyeksi:
	* [http://www.progonos.com/furuti/MapProj/CartIndex/cartIndex.html ~~Map projection concepts~~] by Carlos Furuti		* [http://www.progonos.com/furuti/MapProj/CartIndex/cartIndex.html Konsep proyeksi peta] oleh Carlos Furuti
	* [http://www.csiss.org/map-projections/index.html ~~Map projection gallery~~] by Paul Anderson ([http://www.galleryofmapprojections.com/ old link])		* [http://www.csiss.org/map-projections/index.html Galeri proyeksi peta] oleh Paul Anderson ([http://www.galleryofmapprojections.com/ old link])
	<!-- retained the old link as new one seems to lead to a dead server -->		<!-- retained the old link as new one seems to lead to a dead server -->

	=== ~~Map datums~~ ===		=== Datum peta ===

	* [http://www.colorado.edu/geography/gcraft/notes/datum/datum.html ~~An introduction to geodetic datums~~] by Peter Dana		* [http://www.colorado.edu/geography/gcraft/notes/datum/datum.html Pengantar tentang datum geodetik] oleh Peter Dana
	* [http://home.online.no/~sigurdhu/WGS84_Eng.html ~~How~~ WGS 84 ~~defines the Earth~~]		* [http://home.online.no/~sigurdhu/WGS84_Eng.html Bagaimana WGS 84 mendefinisikan Bumi]
	* A discussion of [http://www.linz.govt.nz/core/surveysystem/geodeticinfo/conversions/datums/nzgd1949-nzgd2000/index.html 3-term, 7-term, ~~and~~ NTv2 grid ~~datum transformations~~] by Land Information New Zealand		* A discussion of [http://www.linz.govt.nz/core/surveysystem/geodeticinfo/conversions/datums/nzgd1949-nzgd2000/index.html 3-term, 7-term, dan NTv2 transformasi datum grid] oleh Land Information New Zealand
	: (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 -->

⚠️Firmanhadi: New page: {{Trans|Bahasa Indonesia}} == Geodesy and Cartography == === Background material === * [http://oceanservice.noaa.gov/education/kits/geodesy/welcome.html An introduction to Geodesy] from ...

2008-09-30T15:37:24Z

New page: {{Trans|Bahasa Indonesia}} == Geodesy and Cartography == === Background material === * [http://oceanservice.noaa.gov/education/kits/geodesy/welcome.html An introduction to Geodesy] from ...

New page

{{Trans|Bahasa Indonesia}}

== Geodesy and Cartography ==
=== Background material ===

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

=== 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.remotesensing.org/geotiff/proj_list/ Projections Transform Lists] (PROJ4)
* [http://www.dmap.co.uk/utmworld.htm UTM Zones]

EPSG:
* [http://www.epsg.org EPSG projection codes]
: [http://www.epsg-registry.org/ EPSG database search]
: [http://spatialreference.org/ Spatialreference community portal]

Projection galleries:
* [http://www.progonos.com/furuti/MapProj/CartIndex/cartIndex.html Map projection concepts] by Carlos Furuti
* [http://www.csiss.org/map-projections/index.html Map projection gallery] by Paul Anderson ([http://www.galleryofmapprojections.com/ old link])


=== Map datums ===

* [http://www.colorado.edu/geography/gcraft/notes/datum/datum.html An introduction to geodetic datums] by Peter Dana
* [http://home.online.no/~sigurdhu/WGS84_Eng.html How WGS 84 defines the Earth]
* A discussion of [http://www.linz.govt.nz/core/surveysystem/geodeticinfo/conversions/datums/nzgd1949-nzgd2000/index.html 3-term, 7-term, and NTv2 grid datum transformations] by Land Information New Zealand
: (besides the web page have a look at the PDF fact sheet and guide linked therein)


==How GRASS deals with geodetics==

As far as GRASS is concerned, an ellipsoid and a spheroid are the same thing, and ellipsoid is the prefered name.

As far as GRASS is concerned, a datum is made up of an ellipsoid and an origin.
Setting a datum is optional, but highly recommended.

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

=== Modules controling a location's map projection ===
* [http://grass.osgeo.org/grass64/manuals/html64_user/g.proj.html 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 ===

* [http://grass.osgeo.org/grass64/manuals/html64_user/r.proj.html r.proj] for reprojecting raster maps
* [http://grass.osgeo.org/grass64/manuals/html64_user/v.proj.html 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

=== 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
* 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
* [http://grass.osgeo.org/grass64/manuals/html64_user/i.rectify.html 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)

;[[Georeferencing]]

==GIS Data types==

===Raster Data===

Data which occurs in a regularly spaced grid. e.g. a satellite image or digital terrain map.<BR>
Region settings determine the spatial extent and resolution of the grid.

;[http://grass.osgeo.org/grass64/manuals/html64_user/rasterintro.html Raster Intro]
[[Replacement raster format]]

[[GRASS Raster Mask]]

[[GRASS raster semantics]]

===3D Raster Data (Voxel)===

A stack of 2D raster maps.

;[http://grass.osgeo.org/grass64/manuals/html64_user/raster3dintro.html Raster 3D Intro]

===Vector Data===

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]
[[Vectordata]]

=== Imagery Data ===
Pixelated photographic or satellite images, often imported from a
[http://en.wikipedia.org/wiki/GeoTIFF GeoTIFF] or PNG image file.

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]

* The GRASS [[Image processing]] wiki page

===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
[http://grass.osgeo.org/grass64/manuals/html64_user/v.in.sites.all.html v.in.sites.all] modules.

==Conversions between data types==

The following table is intended to catalog transformations from one type of data to another:<BR>
''[table is currently incomplete!]''

{| border="1"
| From / To
![http://grass.osgeo.org/grass64/manuals/html64_user/rasterintro.html Raster]
![http://grass.osgeo.org/grass64/manuals/html64_user/raster3dintro.html 3D Raster]
![http://grass.osgeo.org/grass64/manuals/html64_user/vectorintro.html Vector]
|-
! Raster
| r.mapcalc
| r.to.rast3
| r.to.vect, v.sample, r.volume
|-
! 3D Raster
| r3.to.rast, r3.cross.rast
| r3.mapcalc
|
|-
! Vector
| v.to.rast, v.surf.rst, v.surf.idw
| v.vol.rst, v.vol.idw, v.to.rast3
| v.clean
|-
! Data
| r.in.*
| r3.in.*
| v.in.*
|}

==How a GRASS project is organized==

GRASS data is stored in a three level structure, the database, location and mapset. These can be found in a series of nested directories on the user's computer. All three must exist and are set at GRASS startup time.

===The Database===

The directory in which all GIS data is to be stored.

e.g. <tt>~/grassdata/</tt>

===The Location===

A ''location'' is a GRASS project consisting of an area, projection definition (or unprojected), a grouping of mapsets, all with the same projection settings. A location is a subdirectory of the GRASS ''database''.

e.g. world_lat_lon, utm_zone_59, or west_coast

A ''location'' contains one or many ''mapsets''.

===The Mapset===

A ''mapset'' contains map(s), it is a subdirectory of a ''location''.
Conceptually, if several mapsets are used in a location, they may be assigned to different users (each has one or several own mapsets to work in and cannot modify thos of other users), and/or it they are used to organize a project (''location'') by subareas or subprojects.
There are no specific organizational limitations.

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>).

==How the Open Source software development model works==

GRASS differs from many other GIS software packages used in the professional world in that it is developed and distributed by users for users; mostly on a volunteer basis, in the open, and is given away for free.

Emphasis is placed on interoperability and unlimited access to data as well as software flexibility and evolution rate (both added features and bug minimization).

''Free'' can have many meanings, as the links below illustrate, and within a project there is often a spectrum of philosophies and goals amongst developers. But it works - Free Software has revolutionized many sectors of the computing world over the last few years and continues to do so today.

* [http://www.gnu.org/philosophy/philosophy.html Philosophy of the Free Software Movement]
* [http://www.opensource.org The Open Source Initiative has a good explanation]
* [http://www.fsf.org The Free Software Foundation]
* [http://www.gnu.org/copyleft/gpl.html The GNU General Public License]

==Raster GIS Analysis==

===Simple Raster Math===

Sometimes when analyzing the relationship between two or more raster data sets, a relatively simple mathematical approach is best. One example using the r.mapcalc tool would be to look at changes between two raster data sets. By subtracting the values in these two data sets you can assume that resulting cells with a positive value have a possitive change and those with a negative value have negative change. If the cell values have a zero value then there would be no change.

GRASS comes bundled with the r.mapcalc tool as well as the d.m GUI interface for the tool accessable using the r.mapcalculator command. This GUI allows the user to easily assign raster sets 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:Languages/id]]