Wikipedia:WikiProject Geographical coordinates

This is a WikiProject, an area for focused collaboration among Wikipedians. New participants are welcome; please feel free to participate!

Shortcuts

WikiProject Geographical coordinates aims to better organize location information in articles containing a set of numbers that identifies location on and relative to the Earth. In particular, we aim 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.

Quick Geographical coordinates how to

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

To add 57°18′22″N 4°27′32″W / 57.30611°N 4.45889°W / 57.30611; -4.45889 to the top of an article, use {{Coord}}, thus:

{{Coord|57|18|22|N|4|27|32|W|display=title}}

These coordinates are in degrees, minutes, and seconds of arc.

"title" means that the coordinates will be displayed next to the article's title at the top of the page (in desktop view only; title coordinates do not display in mobile view) and before any other text or images. It also records the coordinates as the primary location of the page's subject in Wikipedia's geosearch API.

To add 44°06′45″N 87°54′47″W / 44.1124°N 87.9130°W / 44.1124; -87.9130 to the top of an article, use either

{{Coord|44.1124|N|87.9130|W|display=title}}

(which does not require minutes or seconds but does require the user to specify north/ south and east/west) or

{{Coord|44.1124|-87.9130|display=title}}

(in which the north and east are presumed by positive values while the south and west are negative ones). These coordinates are in decimal degrees.

Degrees, minutes and seconds, when used, must each be separated by a pipe ("|").
Map datum must be WGS84 if possible (except for off-Earth bodies).
Avoid excessive precision (0.0001° is <11 m, 1″ is <31 m).
Maintain consistency of decimal places or minutes/seconds between latitude and longitude.
Latitude (N/S) must appear before longitude (E/W).

Optional coordinate parameters follow the longitude and are separated by an underscore ("_"):

dim: dim:N (viewing diameter in metres)
region: region:R (ISO 3166-1 alpha-2 or ISO 3166-2 code)
type: type:T (landmark or city(30,000), for example)

Other optional parameters are separated by a pipe ("|"):

display
|display=inline (the default) to display in the body of the article only,

|display=title to display at the top of the article only (in desktop view only; title coordinates do not display in mobile view), or

|display=inline,title to display in both places.
name
name=X to label the place on maps (default is PAGENAME)

Thus: {{Coord|44.1172|-87.9135|dim:30_region:US-WI_type:event

|display=inline,title|name=accident site}}

Use |display=title (or |display=inline,title) once per article, for the subject of the article, where appropriate.

Per WP:ORDER, the template is placed at the bottom of the article in the 'end matter', after any navigation templates, but before all categories, including the {{DEFAULTSORT}} template. The {{coord}} template may also be placed within an infobox, instead of at the bottom of the article.
For full details, refer to {{Coord/doc}}.
Additional guidance is available at obtaining coordinates and converting coordinates.

Related WikiProjects

WikiProject Council includes this WikiProject in its Geographical directory. This WikiProject is an offshoot of WikiProject Maps:

WikiProject Geography

WikiProject Maps

WikiProject Geographical coordinates

...and is the parent project of:

Wikipedia-World

Other WikiProjects that make use of geographical coordinates include:

Associated Portals

The AtlasPortal is associated with WikiProject Geography.

The Geography Portal is associated with WikiProject Geography.

Participants

This list has been moved to its own page.

Goals

Should provide a uniform markup for all geographic coordinates
Should provide a user-preferred appearance for all geographic coordinates
Markup should be easy and natural to use
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
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.
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).
Serve as a tool for finding Wikipedia articles describing nearby locations. See also meta:Wikipediatlas.
Adhere to existing Internet standards for geographic coordinates as far as possible^{[clarification needed]} such as using WGS84 for terrestrial coordinates

Usage guidelines

See also MOS:COORDS

In general, coordinates should be added to any article about a location, structure, or geographic feature that is more or less fixed in one place. Such items can vary in size from a single tree (or smaller) to entire oceans or continents. Coordinates should also be added to articles about events that are associated with a single location, for example, the Ufa train disaster. Guidelines for less obvious situations are given below.

Coordinates are appropriate for the top articles or within infoboxes of the following types of articles:

Businesses/organizations with a single location (even if they are defunct)
Demolished buildings/structures
Buildings/structures that have been proposed, but not yet built (if there is a reliable source for the location)
Permanently docked ships (and shipwrecks)

Do not add coordinates to the following types of articles:

Biographies of living people
Works of art (other than permanent outdoor statues, installations or murals)
Sports teams (add to the stadium article instead)
Businesses with multiple locations (although listing coords for individual locations in a table may be appropriate)
Ships that are not permanently docked or sunk

Other types of articles may be decided on a case-by-case basis.

Which coordinates to use

National mapping agencies such as the Geographic Names Information System (GNIS), Ordnance Survey (OS), and Geographical Names Board of Canada (GNBC) are usually reliable sources for coordinates. The GEOnet Names Server (GNS) database is not reliable. Always double check the coordinates on an internet mapping service. For other locations, the following points should be considered:

For villages, towns, communities, etc., use the current centre. Where this is difficult, choose the earliest known settlement of that name. Be aware that the GNIS coordinates may be an arbitrarily chosen civic feature, as that was the usual rule.
For military and industrial establishments (e.g., castles, barracks, dockyards, car plants) use the main gate.
For administrative districts, use the head office.
For geographical features with an area, such as lakes, reservoirs, and islands, use a point reasonably in the center of the feature. (Remember not to specify too much precision; see Precision guidelines below.)
For linear features, see Wikipedia:WikiProject Geographical coordinates/Linear. Be aware that the GNIS primary coordinates will usually be of the feature "mouth" and thus may differ.

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|display=title}}

See also: Obtaining coordinates

Marking project-related pages on Talk page

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

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.Geographical coordinatesWikipedia:WikiProject Geographical coordinatesTemplate:WikiProject Geographical coordinatesGeographical coordinates articles

Implementation details

Coordinate templates

There are two ways of specifying coordinates:

{{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.
Infoboxes – Many infobox templates for places have a parameter, typically |coordinates=, 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.)

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

It has

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

type:T

Shortcut

WP:COORD TYPE

The type: parameter specifies the type of location for reverse mapping (for instance, to select a marker icon in the WikiMiniAtlas).

It also sets the map scale, which can however be overridden by dim: or scale:.

Valid types are:

T	Description	Map scale
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
airport	airports and airbases	1:30,000
city(pop)	cities, towns, villages, hamlets, suburbs, subdivisions, neighborhoods, and other human settlements (including unincorporated and/or abandoned ones) with known population Please replace pop with a number. Commas in pop will be ignored. There should be no blanks.	1:30,000 ... 1:300,000
city	cities, towns, villages, hamlets, suburbs, subdivisions, neighborhoods, and other human settlements (including unincorporated and/or abandoned ones) with unspecified population These are treated as minor cities.	1:100,000
country	(e.g. "type:country")	1:10,000,000
edu	schools, colleges, and universities	1:10,000
event	one-time or regular events and incidents that occurred at a specific location, including battles, earthquakes, festivals, and shipwrecks	1:50,000
forest	forests and woodlands	1:50,000
glacier	glaciers and icecaps	1:50,000
isle	islands and isles	1:100,000
landmark	buildings (including churches, factories, museums, theatres, and power plants but excluding schools and railway stations), caves, cemeteries, cultural landmarks, geologic faults, headlands, intersections, mines, ranches, roads, structures (including antennas, bridges, castles, dams, lighthouses, monuments, and stadiums), tourist attractions, valleys, and other points of interest	1:10,000
mountain	peaks, mountain ranges, hills, submerged reefs, and seamounts	1:100,000
pass	mountain passes	1:10,000
railwaystation	stations, stops, and maintenance areas of railways and trains, including railroad, metro, rapid transit, underground, subway, elevated railway, etc.	1:10,000
river	rivers, canals, creeks, brooks, and streams, including intermittent ones	1:100,000
satellite	geo-stationary satellites	1:10,000,000
waterbody	bays, fjords, lakes, reservoirs, ponds, lochs, loughs, meres, lagoons, estuaries, inland seas, and waterfalls	1:100,000
camera	To indicate the location of where a specific image was taken. This type is used by coordinate templates on File pages.	1:10,000
	Default scale: if no type is used or the type is not defined in the GeoHack extension	1:300,000

Samples
T	Markup	Result
waterbody	`{{coord\|46\|43\|N\|7\|58\|E\|type:waterbody}}`	46°43′N 7°58′E / 46.717°N 7.967°E / 46.717; 7.967

dim:D

The dim: parameter defines the diameter of a viewing circle centered on the coordinates. While the default unit of measurement is metres, the km suffix may be appended to indicate kilometres. The dim: parameter overrides the scale implied by any type: parameter.

Syntax — dim:<width><units>

width — integer number of metres (m) or kilometres (km)

units — m or km, if not specified, defaults to m

GeoHack uses dim: to select a map scale such that the viewing circle appears roughly 10 centimetres (4 in) in diameter on a 72 dpi computer monitor. If no dim:, type:, or scale: parameters are provided, GeoHack uses its default viewing circle of 30 kilometres (19 mi).

Samples
Subject	Dim	Markup	Result
Buckingham Palace	120m	`{{coord\|51.501\|-0.142\|dim:120m}}`	51°30′04″N 0°08′31″W / 51.501°N 0.142°W / 51.501; -0.142
London	10km	`{{coord\|51.507222\|-0.1275\|dim:10km}}`	51°30′26″N 0°07′39″W / 51.507222°N 0.1275°W / 51.507222; -0.1275
Western Hemisphere	10,000 kilometres (6,200 mi)	`{{coord\|0\|N\|90\|W\|dim:10000km}}`	0°N 90°W / 0°N 90°W / 0; -90
Ohio	400 kilometres (250 mi)	`{{coord\|40.5\|-82.5\|dim:400km}}`	40°30′N 82°30′W / 40.5°N 82.5°W / 40.5; -82.5
Dresden	20,000 metres (12 mi)	`{{coord\|51.03\|13.73\|dim:20000}}`	51°02′N 13°44′E / 51.03°N 13.73°E / 51.03; 13.73
Statue of Liberty	100 metres (330 ft)	`{{coord\|40.6892\|-74.0445\|dim:100}}`	40°41′21″N 74°02′40″W / 40.6892°N 74.0445°W / 40.6892; -74.0445

scale:N

Shortcut

WP:COORD SCALE

The scale: parameter specifies the desired map scale as 1:N, overriding the scale implied by any type: parameter.

GeoHack uses scale: to select a map scale for a 72 dpi computer monitor. If no dim:, type:, or scale: parameters are provided, GeoHack uses its default scale of 1:300,000.

Samples
Subject	Scale	Markup	Result
Big Ben	1:500	`{{coord\|51.500611\|N\|0.124611\|W\|scale:500}}`	51°30′02″N 0°07′29″W / 51.500611°N 0.124611°W / 51.500611; -0.124611
Palace of Westminster	1:5,000	`{{coord\|51.5006\|N\|0.1246\|W\|scale:5000}}`	51°30′02″N 0°07′29″W / 51.5006°N 0.1246°W / 51.5006; -0.1246
City of Westminster	1:50,000	`{{coord\|51.501\|N\|0.125\|W\|scale:50000}}`	51°30′04″N 0°07′30″W / 51.501°N 0.125°W / 51.501; -0.125
Greater London	1:500,000	`{{coord\|51.50\|N\|0.12\|W\|scale:500000}}`	51°30′N 0°07′W / 51.50°N 0.12°W / 51.50; -0.12

region:R

Shortcut

WP:COORD REGION

The region: parameter specifies the political region for terrestrial coordinates. It is used to select appropriate map resources. If no region: parameter is provided, GeoHack attempts to determine the region 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.

Examples of ISO 3166-1 alpha-2 codes:

AQ Antarctica
AU Australia
BR Brazil
DE Germany
GB United Kingdom
HK Hong Kong
IN India
LK Sri Lanka
RU Russia
US United States

Examples of ISO 3166-2 region codes:

DE-TH Thuringia, Germany
GB-BIR Birmingham, England
NO-03 Oslo, Norway
US-NY New York state, US

The oceans have the following Wiki assigned code elements per de:Vorlage:Coordinate#Ozeane.

XN Arctic Ocean
XA Atlantic Ocean
XI Indian Ocean
XP Pacific Ocean
XS Southern Ocean

In addition, two Wiki assigned code elements can be used with {{coord}}:

XZ for objects in or above international waters (similar to UN/LOCODE).
ZZ for use in examples.

Samples
Focus region	Region	Markup	Result
Switzerland	`CH`	`{{coord\|46.9524\|N\|7.4396\|E\|region:CH}}`	46°57′09″N 7°26′23″E / 46.9524°N 7.4396°E / 46.9524; 7.4396
Berlin, Germany	`DE-BE`	`{{coord\|52.5164\|N\|13.3775\|E\|region:DE-BE}}`	52°30′59″N 13°22′39″E / 52.5164°N 13.3775°E / 52.5164; 13.3775

globe:G

The globe: parameter specifies the planet, dwarf planet, asteroid, or natural satellite upon which the coordinates reside. Apart from earth (the default), recognized values are: mercury, venus, moon, mars, phobos, deimos, ceres, vesta, jupiter, ganymede, callisto, io, europa, mimas, enceladus, tethys, dione, rhea, titan, hyperion, iapetus, phoebe, miranda, ariel, umbriel, titania, oberon, triton, pluto, and charon.

Samples
Subject	G	Markup	Result
Kittu Crater	ganymede	`{{coord\|0.4\|N\|334.6\|W\|globe:ganymede}}`	0°24′N 334°36′W / 0.4°N 334.6°W / 0.4; -334.6
Viking 2 lander	mars	`{{coord\|48.269\|N\|225.990\|W\|globe:mars}}`	48°16′08″N 225°59′24″W / 48.269°N 225.990°W / 48.269; -225.990
Mozart Crater	mercury	`{{coord\|7.8\|N\|190.5\|W\|globe:mercury}}`	7°48′N 190°30′W / 7.8°N 190.5°W / 7.8; -190.5
Apollo 11 lander	moon	`{{coord\|0\|40\|26.69\|N\|23\|28\|22.69\|E\|globe:moon}}`	0°40′26.69″N 23°28′22.69″E / 0.6740806°N 23.4729694°E / 0.6740806; 23.4729694
Ksa Crater	titan	`{{coord\|14.0\|N\|65.4\|W\|globe:titan}}`	14°00′N 65°24′W / 14.0°N 65.4°W / 14.0; -65.4
Venera 13 lander	venus	`{{coord\|7.5\|S\|303\|E\|globe:venus}}`	7°30′S 303°00′E / 7.5°S 303°E / -7.5; 303
Stickney Crater	phobos	`{{coord\|1\|N\|49\|W\|globe:phobos}}`	1°N 49°W / 1°N 49°W / 1; -49

Very rough mapping is provided on geohack for almost all supported globes. The pop-out WikiMiniAtlas system provides limited mapping for Moon, Mars, Mercury, Venus, Io, and Titan, as of February 2021^[update].

The maps roughly implies a coordinate reference system, but does not clearly specify one (unlike Earth's WGS84). Since the template defaults to east longitude, the |W| direction must be specified for globes that measure longitude westward. For celestial coordinates, use {{Sky}} instead.

source:S

Shortcut

WP:COORD SOURCE

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 an 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, US locations sourced from the similar public domain GNIS database would be tagged as "source:GNIS".

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.

Display preferences

To always display coordinates as DMS values, add this to your common.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 common.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 common.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 common.js:

var wma_settings = {enabled:false}

Note that this will disable WikiMiniAtlas.

Format

format=dec will reformat the coordinates to decimal degrees for all readers.
format=dms will reformat the coordinates to degrees | minutes | seconds (dms) format for all readers.

Creating new templates

When creating new templates or infoboxes, use {{coord}}. Unless a template uses the coordinate data in another way, 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}}.

Linear features

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

How to obtain geographical coordinates

See Obtaining geographic coordinates

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.

Precision guidelines

Shortcut

WP:OPCOORD

Regardless of how coordinates are obtained, consider the precision specified in a Wikipedia article. Reliable secondary sources exist for some locations. Without a reliable source, the larger the object being mapped, the less precise the coordinates need to be. Cities must be specified with a precision of degrees, minutes and seconds to respect historical norms. When the #Which coordinates to use guideline is used, degrees, minutes and seconds or d.dddd are the default. To specify a particular point in the city, such as a building, generally requires precision down to degrees-minutes-seconds or d.dddd° if decimal degrees are used. In the case of objects such as fountains or statues, it may be necessary to use d°m's.s" or d.ddddd°. Higher precisions should be avoided, as they greatly exceed the accuracy of civilian GPS and online mapping services. (Using 4 m accuracy as an estimate for civilian GPS: Depending on the coordinates format and the latitude, the next-higher precisions exceed the accuracy by a factor of somewhere between 13 and 72.)

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 object is smaller than it truly is.

There is no set way to determine object size, and the boundaries of many geographical objects are not clearly defined or not readily available. The difference rarely affects the suggested coordinates precision, so a rough size estimate is usually adequate. However, it should be noted that object size is always linear (one-dimensional), not an area measurement.

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	96.4 km	78.7 km	55.7 km
1′	1.85 km	1.61 km	1.31 km	0.93 km
0.1′	185 m	161 m	131 m	93 m
0.01′	18.5 m	16.1 m	13.1 m	9.3 m
1′′	31 m	27 m	22 m	15 m
0.1′′	3.1 m	2.7 m	2.2 m	1.5 m

Decimal degrees format
Precision	Diff. at equator	Diff. at 30°	Diff. at 45°	Diff. at 60°
1°	111 km	96.4 km	78.7 km	55.7 km
0.1°	11 km	9.64 km	7.87 km	5.57 km
0.01°	1.1 km	964 m	787 m	557 m
0.001°	110 m	96.4 m	78.7 m	55.7 m
0.0001°	11 m	9.64 m	7.87 m	5.57 m
0.00001°	1.1 m	96.4 cm	78.7 cm	55.7 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)

The values in the table give distances in the east-west direction corresponding to a small change in longitude, at different latitudes. You can take the equator columns of the table as a rough guide to distances in the north-south direction that correspond to a small change in latitude, since they vary only a little bit at different latitudes. For simplicity, however, the latitude precision is commonly copied from that of the longitude.

Precision tables

Shortcut

WP:COORDPREC

The following tables show suggested coordinates precisions for various object sizes and latitudes. Refer to the preceding section for more information about coordinates precision. To use these tables:

Choose one of the tables depending on whether you want degrees-minutes-seconds format or decimal degrees format
Find the column that is closest to the latitude of your object
Find the row that is closest to the size of your object
Note the coordinates precision at the intersection of your row and column

Usage example

Example: You want coordinates, in decimal degrees format, for Yosemite National Park, California, U.S.

The size of the object is roughly 70 km
GNIS query gives the Park's location, in decimal degrees, as: 37.8483188 (north latitude), −119.5571434 (west longitude)

To solve:

Choose the Decimal degrees format table
Find the 45° column; 37.8483188 is (slightly) closer to 45° than to 30°
Find the 50 km row; 70 km is closer to 50 km than to 100 km
Note the precision at the intersection of row and column: d.d°
Round to the selected precision: 37.8, −119.6

(This is a good example of a borderline case, as the latitude is quite close to 37.5°, the midpoint between 30° and 45°. If the Park were a mere 25 miles to the south, you would use the 30° column instead, yielding a different precision: d.dd°. You could opt for that precision instead, giving 37.85, −119.56. That's your call. But the table shows that more than two decimal positions would definitely be too precise for this case.)

Degrees-minutes-seconds format
	0°	30°	45°	60°
10 m	d° m' s.s" or d.ddddd° ^{[note 3]}			d° m' s.s"
50 m	d° m' s.s"	d° m' s.s"	d° m' s.s"	d° m' s.s"
100 m	d° m' s.s"	d° m' s.s"	d° m' s.s"	d° m' s"
500 m	d° m' s"	d° m' s"	d° m' s"	d° m' s"
1000 m 1 km	d° m' s"	d° m' s"	d° m' s"	d° m' s"
5 km	d° m' s"	d° m' s"	d° m' s"	d° m'
10 km	d° m'	d° m'	d° m'	d° m'
50 km	d° m'	d° m'	d° m'	d° m'
100 km	d° m'	d° m'	d° m'	d° m'
500 km	d° m'	d°	d°	d°
1000 km	d°	d°	d°	d°

Decimal degrees format
	0°	30°	45°	60°
10 m	d.ddddd°	d.ddddd°	d.ddddd°	d.ddddd°
50 m	d.ddddd°	d.ddddd°	d.dddd°	d.dddd°
100 m	d.dddd°	d.dddd°	d.dddd°	d.dddd°
500 m	d.dddd°	d.dddd°	d.ddd°	d.ddd°
1000 m 1 km	d.ddd°	d.ddd°	d.ddd°	d.ddd°
5 km	d.ddd°	d.ddd°	d.dd°	d.dd°
10 km	d.dd°	d.dd°	d.dd°	d.dd°
50 km	d.dd°	d.dd°	d.d°	d.d°
100 km	d.d°	d.d°	d.d°	d.d°
500 km	d.d°	d.d°	d°	d°
1000 km	d°	d°	d°	d°

The tables are derived from the precision data at § Precision guidelines, above. As suggested there, they use a target resolution of one-tenth of the object size.
The tables are not perfect. Some cases will yield a precision that is different from what you would get by doing the math (including trigonometry) for that specific case. This is because it is impossible to represent all cases correctly in a usable tabular format. The tables provide the correct precision for a majority of cases. Any error should be limited to one level of precision (e.g., d° m' vs. d° m' s", or d.ddd° vs. d.dddd°), which is acceptable for the purposes of Wikipedia coordinates.
d.ddddd° is roughly three times more precise than d° m' s.s".

Mathematical formulas

You can also calculate the kilometers per degree of longitude, k, using one of the following formulas (θ is the latitude, 6378.14 km is the equatorial radius, and 6356.8 km is the polar radius):

Accurate, assuming a spheroid:

$k={\frac {\pi }{180}}\cos(\theta ){\sqrt {\frac {(6378.14^{2}\cos \theta )^{2}+(6356.8^{2}\sin \theta )^{2}}{(6378.14\cos \theta )^{2}+(6356.8\sin \theta )^{2}}}}$

Approximate:

$k=111.3\cos \theta \,$ Equator to latitude 25° (north or south)
$k=111.2\cos \theta \,$ Latitude 30° to 40°
$k=111.1\cos \theta \,$ Latitude 45° to pole

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)

To do list

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.

NASA World Wind Samples

All examples use NASA World Wind, with the Wikipedia overlay. This is purely meant as an example of using a coordinated concept for geographical coordinates.

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, español Layer
static Google-Earth layers in 10 language with different folders (Castles, Parks,...), Download at webkuehn.de
SQL-Data of all scanned coordinates

Copernix.io - View and search Wikipedia Articles on a map

Copernix.io is a geographical search engine allowing users to search places and information from Wikipedia on a map. Users can leave the search bar empty to see all pages within an area or type a query to get subject specific information.

Some useful examples can be found at:

Copernix examples and about

The main search page is at:

Copernix.io

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.

WikiMiniAtlas JavaScript plugin

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 to 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).

All geodata in SQL file format

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

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 {{GeoGroup}} 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:

Wikitude provides coordinates as KML or TomTom POI format.

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`
Settlements whose populations are under 1,000	`type:city$[0-9]{0,3}$`
South of the Antarctic Circle (approximate)	`=(66_[3-9]\|66.[6-9]\|6[7-9]\|[7-9][0-9])[0-9_.]*_S_`
Coordinates equivalent to 0°N 0°E / 0°N 0°E / 0; 0	`=[-_0.]+[NS][-_0.]+[EW]`
Coordinates in San Marino	`region:SM`
Coordinates on Callisto	`globe:[Cc]allisto`

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

Searches to find problems
Problem description	Python regular expression
Excess precision (6 or more decimal places)	`[.][0-9]{6}`
Excess precision (5 decimal places)	`[.][0-9]{5}[^0-9]`
Coordinates lacking metadata (no type or region)	`_[WE]_+($\|&title=\|\{+[0-9]\}+)`
Unexpected character in parameter name	`params=[^&=]?[^_a-z][a-z]:`
Unsupported parameter elevation:	`params=[^&=]+?elevation:`
Unsupported parameter other than elevation:	`params=[^&=]+?([^emn]\|cation\|me\|om):`
Malformed region code	`params=[^&=]+?region:([^A-Z]\|[A-Z]([^A-Z]\|[A-Z][^_&-]\|[A-Z]-[^0-9A-Z]))`
Unassigned top-level region code	`region:(A[ABCHJKPVY]\|B[CKPX]\|C[BEJPQT]\|D[^EJKMOZ]\|E[ABDI-LUW]\|F[A-HLNPQS-Z]\|G[CJKOVXZ]\|H[A-JLOPQSV-Z]\|I[A-CF-KPU-Z]\|J[^EMOP]\|K[A-DFJ-LOQS-VX]\|L[D-HJL-QWXZ]\|M[BIJ]\|N[BDHJKMNQSV-Y]\|O[^M]\|P[B-DIJOPQUVXZ]\|Q[^A]\|R[^EOSUW]\|S[PQUW]\|T[ABEIPQSUXY]\|U[^AGMSYZ]\|W[^FS]\|X[^AINPSZ]\|Y[^ET]\|Z[^AMW])`
Unexpected character in dim or scale or typesize	`(dim:[0-9.]([^0-9.k_&]\|k[^m]))\|(scale:[0-9][^0-9_&])\|(city[(][0-9,]*[^0-9,)])`
Incomplete parameter	`params=[^&=]*?(dim\|globe\|region\|scale\|source\|type):?(&\|_\|$)`
Invalid type	`type:(?!(adm(1st\|2nd\|3rd)\|airport\|city\|country\|edu\|event\|forest\|glacier\|isle\|landmark\|mountain\|pass\|railwaystation\|river\|satellite\|waterbody)($\|[&_()]))`
City without type:	`params=[^&=]*?[^:]city`
College with type: other than edu	`[Cc]ollege[&].*?type:(?!edu)`
School with type: other than edu	`[Ss]chool[&].*?type:(?!edu)`
University with type: other than edu	`[Uu]niversity[&].*?type:(?!edu)`
United States broadcaster with type: other than landmark	`[^(][KW][A-Z][A-Z][A-Z].?params=.?type:(?!landmark)`
Station with type: other than railwaystation	`ailway_[Ss]tation.*?type:(?!railwaystation)`
Typesize provided for type other than city	`type:(?!city)[^&=_]*[(]`
Unusual URL formatting	`geohack.php[?](?!pagename=)\|&language=`
Tallies

WikiProject Geographical coordinates categories

WikiProject Geographical coordinates

WikiProject Geographical coordinates pages

Articles missing geocoordinate data by country

Articles missing geocoordinate data by sea or ocean

Articles missing geocoordinate data by subject

Articles needing coordinates

Articles not needing geocoordinates

Articles requiring geodata verification

Articles with multiple coordinates but no title coordinates

Articles with OS grid coordinates

Articles with unknown geocoordinates

Wikipedia cave articles with referenced coordinates

Wikipedia cave articles with unreferenced coordinates

Coord template needing repair

Coordinates templates needing maintenance

Pages requiring geodata verification

WikiProject Geographical coordinates participants

Talk pages requiring geodata verification

Articles missing coordinates with coordinates on Wikidata

Articles missing coordinates without coordinates on Wikidata

Coordinates not on Wikidata

Coordinates Wikidata tracking categories

Coordinates templates

WikiProject Geographical coordinates templates

World map displaying the concentration of wikipoints

Wikipedia-World allows generating such maps (see here)

References

External links

3.4.2 GEO type definition to specify information related to the global positioning of the object that a vCard represents.RFC2426
How latitude and longitude are stored in a DNS record.RFC1876
Memo describing a method of adding simple geographic position information to HTTP transactions using extension headers.[2]
Memo describing a method of registering HTML documents with a specific geographic location through means of embedded META tags.[3]
Proposal to create a new IANA Time Zones registration process as a central repository for time zone names.[4]
WikiProject Geographical coordinates hot articles watchlist.[5]^{[dead link‍]}

v t e WikiProject Council
WikiProject guides	WikiProject Council Talk Guidelines/Intro WikiProjects Task forces Technical notes Assessment FAQ Work via WikiProjects
Directories and summaries	Directory Proposals Deletion Signpost Shortcuts Popular pages Database reports Watchers
Culture and the arts	Arts Music Performing Plastic Visual Broadcasting Crafts and hobbies Entertainment Games and toys Food and drink Internet culture Language and literature Biography Linguistics Media Philosophy and religion Sports
Geographical	Bodies of water Cities Countries Africa Americas Asia Europe Oceania Landforms Maps Parks, conservation areas and historical sites
History and society	History and society Business and economics Education Military and warfare Politics and government Transportation
Science, technology and engineering	Science Biology Chemistry Economics Geosciences Information science Mathematics Medicine Meteorology Physics Space Technology Time
Wikipedia assistance and tasks	Contents systems Maintenance Files Article improvement and grading Classroom projects WikiProjects

Related WikiProjects

Associated Portals

Participants

Goals

Usage guidelines

Which coordinates to use

Markup

Marking project-related pages on Talk page

Implementation details

Coordinate templates

Parameters

type:T

dim:D

scale:N

region:R

globe:G

source:S

Name

Display preferences

Format

Creating new templates

Linear features

How to obtain geographical coordinates

Geodetic system

Precision guidelines

Precision tables

Mathematical formulas

Coordinates from other language versions (iwcoor)

To do list

Find coordinates for

Tag articles needing coordinates

Fix

More

Tools and applications based on coordinates from Wikipedia

NASA World Wind Samples

View Wikipedia in Google Earth

Copernix.io - View and search Wikipedia Articles on a map

Visualization of Wikipedia articles with Google Maps

WikiMiniAtlas JavaScript plugin

All geodata in SQL file format

Export multiple coordinates

Coordinates search tool

WikiProject Geographical coordinates categories

World map displaying the concentration of wikipoints

See also

References

External links