Wikipedia:WikiProject Geographical coordinates

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World Wind displaying WP coordinates (see applications below)
Shortcuts:
WP:GEO
WP:GEO COOR

Any Wikipedian may participate in this project to better organize information in articles containing geographical coordinates. This page and its subpages contain suggestions; it is hoped that this project will help to focus the efforts of other Wikipedians. If you would like to help, please include yourself as participant, inquire on the talk page and see the to-do list there.

NOTE: This is a concept currently under development, so this is subject to change.

Quick "how to"
To add the coordinates 57°18′22"N 4°27′32"W to the top of an article, use
{{coord|57|18|22|N|4|27|32|W|display=title}}

These coordinates are in the format degrees/minutes/seconds
For decimal coordinates, such as 44.112°N 86.913°W, use one of
{{coord|44.112|N|87.913|W|display=title}}
{{coord|44.112|-87.913|display=title}}
Values (including degrees, minutes and seconds) are separated by a pipe ("|").
Latitude (N/S) before longitude (E/W). Map datum is WGS84.
To display the coordinates in the article as well, use "display=inline,title" instead of "display=title".
Please don't be overly precise (0.0001° is <11 m, 1′′ is <31 m).
Optional parameters:

Full example: {{coord|44.112|-87.913|region:US-WI_type:landmark|display=inline,title}}
For full details on the use of {{coord}}, see Template:Coord
See also: Obtaining coordinates, coordinate conversion
  • For a village, use the current centre. Where this is difficult, choose the earliest known settlement of that name.
  • For military and industrial establishments (e.g. castles, barracks, dockyards, car plants) use the main gate.
  • For administrative districts, use the head office.
  • For linear features see Wikipedia:WikiProject Geographical coordinates/Linear.


Contents

[edit] Title

WikiProject on Geographical coordinates

[edit] Scope

This WikiProject aims primarily to establish a standard for uniform handling of latitude and longitude coordinates as given in various Wikipedia articles, somewhat analogous to how ISBN numbers are handled.

[edit] Related WikiProjects

Parent: WikiProject Maps, then WikiProject Geography

Descendant: Wikipedia-World

[edit] Similar WikiProjects

Other WikiProjects that make use of geographical coordinates include:

[edit] Participants

Userbox: {{User WikiProject Geographical_coordinates}}

[edit] Goals

  1. Should provide a uniform markup for all geographic coordinates
  2. Should provide a user-preferred appearance for all geographic coordinates
  3. Markup should be easy and natural to use
  4. ☑.svg Should be able to have a uniform, extensible way of accessing all types of map resources, avoiding having direct external links to maps in articles
  5. ☑.svg Clicking on a reference navigates directly to a page with external pointers to various resources, with coordinates automatically embedded where possible. The resources can be maps of various kinds, topological charts, satellite photos and others.
  6. ☑.svg Create a database of points, enabling generation of navigatable maps with a clickable icon appearing for every location for which there is a Wikipedia article. This has been implemented for NASA World Wind, Google Earth (see below) and Google maps (see below).
  7. ☑.svg Serve as a tool for finding Wikipedia articles describing nearby locations. See also meta:Wikipediatlas.
  8. Adhere to existing Internet standards for geographic coordinates as far as possible

[edit] Markup

The practical usage of coordinate markup in Wikipedia is described in the style guide for geographical coordinates. For use on maps and other services, parameters may also be required.

A complete entry could for example be: {{coord|51|28|40|N|0|0|6|W|type:landmark_scale:2000_region:GB}}

See also: Obtaining coordinates

[edit] Marking project-related pages on Talk page

The template {{WPcoord}} may be added to relevant Talk pages. This adds the page to several categories and displays as:

WikiProject Geographical coordinates
WikiProject Geographical coordinates is of interest to WikiProject Geographical coordinates, which encourages the use of geographical coordinates in Wikipedia. If you would like to participate, please visit the project page, where you can join the project and see a list of open tasks.

[edit] Implementation details

[edit] Coordinate templates

There are two ways of specifying coordinates:

  1. {{coord}} - Accepts multiple data formats and supports a style sheet preference for display format, plus a Geo microformat. Coord may be placed anywhere in the article source text, inline, with prose text. For example "Mount Everest is at {{coord|27|59|16|N|86|56|40|E}}", which displays as "Mount Everest is at 27°59′16″N 86°56′40″E / 27.98778°N 86.94444°E / 27.98778; 86.94444". To display coordinates at the page's top, near the article's title, in a skin-dependent way, use display=title (see example at Krasnoyarsk hydroelectric dam). To display both inline and top, use display=inline,title.
  2. Infoboxes - Many infobox templates for places have a field for specifying a place's coordinates. The template internally uses {{coord}} and may therefore also display in the title area. See Template:Infobox Settlement and Template:Infobox Mountain for documentation, or, usage examples at Los Angeles and Mount Everest.

(Before September 2008, there was a widely-used family of templates of the form coor .... These are deprecated and have been replaced by {{coord}}. For an overview of choices: WikiProject Geographical coordinates/comparison.)

[edit] Parameters

Following the geographical coordinate, further parameters can optionally be supplied, separated by underscores. This helps display suitable map resources (see Template:GeoTemplate), and will help Wikimaps become fully functional.

For example:

{{coord|61.1631|-149.9721|type:landmark_globe:earth_region:US-AK_scale:150000_source:gnis|name=Kulis Air National Guard Base}} displays 61°09′47″N 149°58′20″W / 61.1631°N 149.9721°W / 61.1631; -149.9721 (Kulis Air National Guard Base)

It has

  • type:landmark
  • globe:earth
  • region:US-AK
  • scale:150000
  • source:gnis

[edit] type:T

Sets the type of this location, which will be used for the reverse mapping of the points. Type will set default map scale. If the default map scale is not appropriate, consider adding a scale:N parameter.

It is also used to select marker icons for the WikiMiniAtlas.

Types are:

Type Description Scale
country (e.g. "type:country") 1:10,000,000
satellite geo-stationary satellites 1:10,000,000
adm1st Administrative unit of country, 1st level (province, state), see table, e.g. U.S. states 1:1,000,000
adm2nd Administrative unit of country, 2nd level, see table, e.g. County (United States) 1:300,000
adm3rd Administrative unit of country, 3rd level, see table 1:100,000
state Former country or administrative unit of country, undefined level (1:100,000)
city(pop) City, town or village with specified population. Commas will be ignored in pop. There should be no blanks. 1:30,000 ... 1:300,000
city City, town or village, unspecified population. Will be treated as a minor city. 1:100,000
airport 1:30,000
mountain peaks, mountain ranges 1:100,000
isle Isles, islands 1:100,000
waterbody Bays, fjords, lakes, reservoirs, ponds, lochs, loughs, meres, lagoons, estuaries, inland seas... 1:100,000
forest Forests and woodlands 1:50,000
river Rivers and canals 1:100,000
glacier Glaciers, ice caps 1:50,000
event One-time or regular events and incidents that occurred on a specific location, e.g. battles 1:50,000
edu Schools, colleges, universities 1:10,000
pass mountain passes 1:10,000
railwaystation stations and stops of railway, train, railroad, metro, rapid transit, underground, subway, elevated railway, etc. 1:10,000
landmark Cultural landmark, building of special interest, tourist attraction and other points of interest. 1:10,000
Default scale: if no type is used or the type is not defined in the geohack extension 1:300,000

Scales in parentheses aren't defined yet in the geohack extension. The definition of type:state was changed.

Sample:

[edit] scale:N

Sets the desired map scale as 1:N. This will override the scale determined by the type:T parameter. If no type and scale parameters are defined, the default scale of the extension will be used (1:300,000).

The scale: parameter can be omitted.

Samples
Scale Markup Result
1:1000 {{coord|51.500611|N|0.124611|W|scale:1000}} 51°30′02″N 0°07′29″W / 51.500611°N 0.124611°W / 51.500611; -0.124611
1:10,000 {{coord|51.500611|N|0.124611|W|scale:10000}} 51°30′02″N 0°07′29″W / 51.500611°N 0.124611°W / 51.500611; -0.124611
1:100,000 {{coord|51.500611|N|0.124611|W|scale:100000}} 51°30′02″N 0°07′29″W / 51.500611°N 0.124611°W / 51.500611; -0.124611
1:1,000,000 {{coord|51.500611|N|0.124611|W|scale:1000000}} 51°30′02″N 0°07′29″W / 51.500611°N 0.124611°W / 51.500611; -0.124611

If the links to the map sites are correctly configured on GeoTemplate and a map is available for the scale, a corresponding map may be displayed.

[edit] region:R

Sets the preferred map region of coverage, used in selecting appropriate map resources for the area. If no region parameter is supplied, the geohack extension attempts to determine it from the coordinates.

The region should be supplied as either a two character ISO 3166-1 alpha-2 country code, or an ISO 3166-2 region code. E.g:

Samples:

Specific code:

  • XZ is used for objects in/above international waters (similar to UN/LOCODE).
  • ZZ is used in samples

[edit] globe:G

Specifies other worlds than Earth, such as Moon, Mars, Venus, Mercury.

Most features of the geohack extension are not made for other globes.

[edit] source:S

Specifies, where present, the data source and data source format/datum, and optionally the original data, presented in parentheses. This is initially primarily intended for use by geotagging robots, so that data is not blindly repeatedly copied from format to format and Wikipedia to Wikipedia, with progressive loss of precision and attributability.

Examples:

  • A lat/long geotag derived from a Ordnance Survey National Grid Reference NM 435 355 found in the English-language Wikipedia would be tagged as "source:enwiki-osgb36(NM435355)"
  • A latitude-longitude location sourced from data taken from the German-language Wikipedia would be tagged as "source:dewiki" -- and so on, for other language codes;
  • A location sourced from the public domain GeoNet Names Server database would be tagged as "source:GNS". No datum or format information is needed, since by default all Wikipedia coordinates are in latitude/longitude format based on the WGS84 datum. Similarly, U.S. locations sourced from the similar public domain GNIS database would be tagged as "source:GNIS".

[edit] name

{{coord}} takes |name=name

If an article contains several display=inline coordinates, each of these may be supplied with a unique name. This name will be used to display the coordinate on the WikiMiniAtlas, and will cause the template to emit an hCard microformat using that name, even if used within an existing hCard. Do not use when the name is that of a person (e.g for a gravesite), as the generated hCard would be invalid. Also, do not use square brackets in names.

[edit] Display

By default coordinates are displayed in the format in which they are specified.

To always display coordinates as DMS values, add this to your monobook.css:

.geo-default { display: inline }
.geo-nondefault { display: inline }
.geo-dec { display: none }
.geo-dms { display: inline }

To always display coordinates as decimal values, add this to your monobook.css:

.geo-default { display: inline }
.geo-nondefault { display: inline }
.geo-dec { display: inline }
.geo-dms { display: none }

To display coordinates in both formats, add this to your monobook.css:

.geo-default { display: inline }
.geo-nondefault { display: inline }
.geo-dec { display: inline }
.geo-dms { display: inline }
.geo-multi-punct { display: inline }

If CSS is disabled, or you have an old copy of MediaWiki:Common.css cached, you will see both formats. (You can either clear your cache or manually refresh this URL: [1].)

To disable display of the blue globe adjacent to coordinates, add this to your monobook.js

var wma_settings = {enabled:false}

Note that this will disable WikiMiniAtlas

See also Wikipedia:Manual of Style (dates and numbers)#Geographical coordinates.


[edit] Creating new templates

When creating new templates or infoboxes, use {{coord}}. Unless a template uses the coordinate data in another way (such as creating a dot on a standard map), the {{coord}} template should be the field value. For example, {{infobox lake}} accepts coords = {{coord|45|N|6|E|type:waterbody}}.

If coordinate data are used directly by a template, use the following parameter names for coordinates:

  • lat_d
  • lat_m
  • lat_s
  • lat_NS
  • long_d
  • long_m
  • long_s
  • long_EW

A provision for accepting decimal coordinates is recommended. For example, allow lat_d = 45.678 | long_d = -123.456 and omission of the remaining parameters.

Where the United Kingdom's Ordnance Survey grid references are used as the coordinates, use {{oscoor}}.

For articles which have no coordinates, but need them, use {{coord missing}}.

[edit] Linear features

For draft guidance on, and examples of, coordinates for linear features (rivers, roads, bridges, tunnels, etc.), see Wikipedia:WikiProject Geographical coordinates/Linear.

[edit] How to obtain geographical coordinates

See Obtaining geographic coordinates

See also: Category:Articles needing coordinates, Maybe-Checker

[edit] Geodetic system

All coordinates specified through {{coord}} must be referenced to WGS84, or an equivalent datum. WGS84 is required for some of the conversions done by the geohack extension.

British national grid references of the Ordnance Survey use its own OSGB36 datum, which is correct for use in national grid references; the correct transformations will automatically be applied when national grid coordinates are used in {{oscoor}} tags. However, OSGB36 latitude/longitude coordinates should not be used anywhere in Wikipedia; please use WGS84 lat/long instead.

[edit] Precision

Regardless of how coordinates are obtained, consider the precision specified in a Wikipedia article. Generally, the larger the object being mapped, the less precise the coordinates should be. For example, the location of a city can be specified with a precision of 100 meters, or even 1 km. To specify a particular point in the city, such as the central administrative building, or a fountain would justify precisions down to 10 meters or even one meter in some cases.

A general rule is to give precisions approximately one tenth the size of the object, unless there is a clear reason for additional precision. Overly precise coordinates can be misleading by implying that the geographic area is smaller than it truly is.

In the two most-used coordinate representations, degrees-minutes-seconds and decimal degrees, precision is, as a useful approximation,

Degrees-minutes-seconds format
Precision Diff. at equator Diff. at 30° Diff. at 45° Diff. at 60°
1° 111 km (~100 km) 96.4 km 78.7 km 55.7 km
1′ 1.85 km (~2 km) 1.61 km 1.31 km 0.93 km
0.1′ 185 m 161 m 131 m 93 m
1′′ 31 m (~30 m) 27 m 22 m 15 m
0.01′ 18.5 m 16.1 m 13.1 m 9.3 m
0.1′′ 3.1 m (~3 m) 2.7 m 2.2 m 1.5 m
0.01′′ 31 cm (~30 cm)
(~1 ft)		 27 cm 22 cm 15 cm
Decimal degrees format
Precision Diff. at equator Diff. at 30° Diff. at 45° Diff. at 60°
1° 111 km (~100 km) 96.4 km 78.7 km 55.7 km
0.1° 11 km (~10 km) 9.64 km 7.87 km 5.57 km
0.01° 1.1 km (~1 km) 964 m 787 m 557 m
0.001° 110 m (~100 m) 96.4 m 78.7 m 55.7 m
0.0001° 11 m (~10 m) 9.64 m 7.87 m 5.57 m
0.00001° 1.1 m (~1 m) 96.4 cm 78.7 cm 55.7 cm
0.000001° 11 cm (~10 cm)
(~4 in)		 9.64 cm 7.87 cm 5.57 cm

Conversions: 1 kilometre (0.621 mi), 1 metre (3.28 ft), 1 centimetre (0.394 in); 1 mile (1.61 km), 1 foot (0.305 m), 1 inch (2.54 cm)

Distances along lines of latitude are the same at the equator but shrink toward the poles. Unless there is specific reason to take this into account, the distances along lines of longitude should suffice as a guide.

You can calculate the number of kilometers per degree of longitude using one of the following approximation formulas (θ is the latitude in degrees):

Best: k = \frac{\pi\cos(\theta)\sqrt{\frac{(6378^2\cos(\theta))^2+(6357^2\sin(\theta))^2}{(6378\cos(\theta))^2+(6357\sin(\theta))^2}}}{180}

Better: k = \frac{2\pi6378\cos(\theta)}{360}\, (6378 is Earth radius at equator)

Sufficient: k = 111.3171\cos(\theta)\,

[edit] Coordinates from other language versions (iwcoor)

Import of coordinates from other wikis
  • conversions are done based on external links to mapsources in other languages
  • the iwlog determines primary coordinates for articles in other languages
  • in general, primary coordinates are imported to this wiki
  • coordinates are used to replace {{coord missing}} with {{coord}} with the parameter display=title
  • dms or decimal format is kept, format=dms can be added to decimal coordinates
  • negative coordinates followed by N or E are converted to positive coordinates followed by S or W
  • coordinates are not imported if:
    • degrees are out of range (90°/180°)
    • minutes or seconds >= 60
    • region doesn't start with [a-zA-Z][a-zA-Z]
    • type is not in list. A few are corrected (e.g. village=>city, lake=>waterbody, dam=>landmark, island=>isle). coordinates with type:state are not converted. Numbers other than population are stripped.
    • globe is present
  • scale is kept, zoom from nl: converted to scale. scale can be dropped if it's equivalent to the one determined by type
  • source is set to "xxwiki" (xx being the wiki the coordinates are imported from). An additional string can be added to differentiate one bot from others (e.g. "-x"). If source: is used in the other language, the previous element is added after a slash, e.g. source:gnis imported from xx: wiki => source:xxwiki-gnis
  • region is set to uppercase, type and scale to lowercase
  • other elements are discarded
Last updated: 16:02, 6 April 2009 (UTC)

[edit] To do list

edit · history · watch · refresh  To-do list for Wikipedia:WikiProject Geographical coordinates:

[edit] Find coordinates for

Use Maybe-Checker: verify and/or add coordinates to articles in categories likely to need coordinates.

Artilces are also listed on WolterBot's cleanup listings (User:WolterBot/Cleanup statistics)

See also: Wikipedia:Obtaining geographic coordinates

[edit] Tag articles needing coordinates

{{coord missing|country name}} is added to articles needing coordinates. This makes them available for the previous step.

[edit] Fix

Fix coordinates possibly pointing to the wrong location:

Fix coordinates with formatting errors:

[edit] More

[edit] Tools and applications based on coordinates from Wikipedia

Articles (and coordinates) can be found through the pages using the templates in Category:Coordinates templates

All coordinates are available for download in Wikipedia database dumps. To get the coordinates from the XML format dump of all articles (enwiki-latest-pages-articles.xml.bz2, 4 GB), the dump needs to be parsed for pages containing coordinates in the entry formats listed above. Most articles in Wikipedia conform to these formats and coordinates are easy to parse from the wikitext with regular expressions for simple character sequences. As all coordinates link to the same PHP tool, they may also be found from the SQL format table of external links (enwiki-latest-externallinks.sql.gz, 725MB). This second method will however not include all available information about the coordinates, such as their position between the article body and the title area.

There may exist some groups of articles that generate the coordinate data dynamically and are not in any of the standard entry formats, as some editors may have wished to facilitate entry of common coordinate related information, while only keeping the output similar with the existing templates. To get all such coordinates, all the articles in the database dump need to be run through a wikitext parser (such as the PHP one in MediaWiki) to expand all the templates, and the result parsed for coordinates. Alternatively, it is also possible to download the HTML generated from all the article and expanded template content (wikipedia-en-html.tar.7z, 14 GB).

Note that mass downloading individual pages from the live Wikipedia site is strongly discouraged and may lead to discontinued access.

[edit] NASA World Wind Samples

All examples use NASA World Wind, with the Wikipedia overlay. This is purely meant as an example of one thing that a coordinated concept for geographical coordinates can be used for.

Links to Wikipedia articles are represented by yellow rings, such as in this view of the Washington DC National Mall, using USGS aerial photos
This view of San Francisco is done using Landsat 7 satellite images. Again, note the rings that indicate Wikipedia articles
Combining radar topographic (Shuttle Radar Topography Mission) data with Landsat-7 images allows full 3D visualization, producing images like this one, of Mount Baker. The upper ring is for the Space Needle. Note also that vertical exaggeration is enabled.

[edit] View Wikipedia in Google Earth

Project Wikipedia-World scan 11 Dumps (ca,cs,de,en,eo,es,fi,fr,nl,pt,ru) and provides:

  • dynamic Google-Earth layers in 21 languages. For instance: english Layer
  • static Google-Earth layers in 10 language with different folders (Castles, Parks,...), Download at webkuehn.de
  • SQL-Data off all scanned coordinates

[edit] Visualization of Wikipedia articles with Google Maps

  • www.geonames.org over 800,000 Wikipedia articles in 230 languages on Google maps. The placemarks include short descriptions of the displayed items, extracted from the Wikipedia articles. Webservices for full text search and reverse geocoding of wikipedia articles.

[edit] WikiMiniAtlas JavaScript plugin

WikiMiniAtlas in action

WikiMiniAtlas is a JavaScript to add to your monobook.js. It adds a draggable and zoomable (just like GoogleMaps) map to all geo-coded articles. Clickable labels with links other geocoded articles are placed on the map to allow spatial browsing of wikipedia. Map layers include satellite images (using Landsat7 data) with zoomlevels down to a resolution <100m, and daily updated MODIS satellite data.

WikiMiniAtlas is currently enabled on Wikipedia (by clicking on the globe () beside the coordinates).

[edit] All geodata in SQL file format

  • Project Wikipedia-World, provides the complete database for download in SQL-file format.

[edit] Export multiple coordinates

Kmlexport tool: Pages marked with multiple coordinates or categories of articles with coordinates can be exported as KML (for use in Google Earth, for example). This tool and some alternatives can be found on clicking the coordinates or by applying the {{GeoGroupTemplate}} template on a page.

The Kmlexport can be used directly or through Google Maps; see for example Colmar Pocket or Category:Capitals in Europe. Export from articles is real-time, export from categories is based on stored extractions (may be several weeks old).

KML may be converted in other formats, suitable as Points of Interest (POI) for GPS systems.

Other sources:

[edit] Coordinates search tool

tools:~dispenser/cgi-bin/geosearch.py allows for regular expression searching on the GeoHack links in the external links table. This has the advantages of near real time information and powerful pattern matching. The following are some example queries created as a demonstration of the flexibility of the system.

edit
Sample searches
Description MySQL Regular expression query
Coordinates imported from the CSWiki _source:cswiki
Cities whose populations are under 1,000 _type:city_*\([0-9]{0,3}\)
Antarctic Circle (approximate) =(66_[3-9]|66.[6-9]|6[7-9]|[7-9][0-9])[0-9_.]*_S_
Locations near Manhattan, NY =40(_4[2-9]|.7|.8[0-5])[0-9_.]*_N_(73_5[5-9]|73.9|74_0?[0-2]|74.0)[0-9_.]*_W

To switch to other wikis, the site parameter can be added to the URL, e.g.

  • &site=commons for Commons
  • &site=pt for Portuguese Wikipedia
Error detection
Description MySQL Regular expression query Status Date
Articles missing metadata (no type or region) _[WE]_+($|&title|\{+[[:digit:]]\}+) many
Missing W/E _[NS]_[^WE]+_*($|&title|\{+[[:digit:]]\}+) 490 2008-08-30
N/S mixed up with E/W _[EW]_[0-9._]+_[NS]_+ ☑.svg 2008-08-30
coordinates with "O"
for W (Oeste) or E (Ost)		 _[NS]_[^WE]+O ☑.svg 2008-09-02
Bad template parameters \{\{\{[3468]\}\}\} 50 2008-08-23
missing ":" in parameters _(region|source|scale|globe|type)_+ ☑.svg 2008-12-06
location: instead of region: location: ☑.svg 2008-08-24
non standard region codes region:[^A-Z] ☑.svg 74+24 2008-08-31
invalid region codes region:(UK|EU|FL|JA) ☑.svg 2008-08-30
invalid region codes region:(JA|LF|PI|RA|RB|RC|RH|RI|RL|RM|RN|RP|WG|WL|WV|YV|O[A-LN-Z]|R[A-DF-NP-R]|Z[B-LN-VX-Z]|Q[B-Z]|X[AY]|UK|EU|AA|FL|EW|DY) ☑.svg 1 2008-08-30
text as region code region:[A-Z][^A-Z] 23 2008-08-31
invalid types type:(school|university) ☑.svg 2008-08-30
invalid types type:island ☑.svg 1 remains (database bug) 2008-08-24
invalid types type:lake ☑.svg none remain 2008-12-08
parameters in caps (Scale:|Type:|Region:|Source:) ☑.svg 6 2008-09-02
elements from samples (optional|type:T|region:ZZ|globe:G) 32 2008-09-03

[edit] World map displaying the concentration of wikipoints

Wikipedia-World allows generating such maps (see here)


[edit] See also

[edit] External links

References

Retrieved from "http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Geographical_coordinates"
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