# WikiProject Geographical coordinates

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.

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

right displaying WP coordinates (see applications below)</center>]]

## 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: Template:Multicol

• Meta:Category:Wikimaps
• WikiProject Cities
• WikiProject Countries
• WikiProject Glaciers
• WikiProject Lakes
• WikiProject Microformats Geo
• WikiProject Mountains
• WikiProject OpenStreetMap
• WikiProject Protected areas
• WikiProject Rivers
• WikiProject U.S. counties
• WikiProject United States

## Associated Portals

100px The AtlasPortal is associated with WikiProject Geography.

100px The Geography Portal is associated with WikiProject Geography.

## Participants

This list has been moved to its own page.

## Goals

1. 30px Should provide a uniform markup for all geographic coordinates
2. 30px Should provide a user-preferred appearance for all geographic coordinates
3. 30px Markup should be easy and natural to use
4.  ?.svg 30px 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. 30px Adhere to existing Internet standards for geographic coordinates as far as possible

## Usage guidelines

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 statues or murals)
• 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 reliable sources for coordinates. The GEOnet Names Server (GNS) database is not reliable. 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.
• For military and industrial establishments (e.g., castles, barracks, dockyards, car plants) use the main gate.
• For linear features, see Wikipedia:WikiProject Geographical coordinates/Linear.

## 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}}

### 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: Template:WikiProject Geographical coordinates

## Implementation details

### Coordinate templates

There are two ways of specifying coordinates:

1. Template:Tlx – 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 Template:Coord". 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 Template:Tl 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 Template:Tl. 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:

Template:Tlx displays Template:Coord

It has

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

#### Name

Template:Tl takes |name=name

#### Creating new templates

When creating new templates or infoboxes, use Template:Tl. Unless a template uses the coordinate data in another way (such as creating a dot on a standard map), the Template:Tl template should be the field value. For example, Template:Tl 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 Template:Tlx.

For articles which have no coordinates, but need them, use Template:Tlx.

### 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 Template:Tl 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 Template:Tl tags. However, OSGB36 latitude/longitude coordinates should not be used anywhere in Wikipedia; please use WGS84 lat/long instead.

### Template:AnchorPrecision guidelines

Template:Shortcut 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°
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°
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

The values in the table give distances in the east-west direction corresponding to a small change in longitude, at different latitudes. You can also 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.

You can also calculate the kilometers per degree of longitude using one of the following approximation formulas (? is the latitude in degrees, 6378 km is the equatorial radius, and 6357 km is the polar radius):

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: $k = \frac{2\pi6378\cos(\theta)}{360}\,$

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

### 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 Template:Tl with Template:Tl 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
• 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
Last updated: 16:02, 6 April 2009 (UTC)

## 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).

### 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.

 thumb National Mall, using USGS aerial photos]] thumb is done using Landsat 7 satellite images. Again, note the rings that indicate Wikipedia articles]] thumb) data with Landsat-7 images for full 3D visualization, as in this image of Mount Baker. Upper ring is for the Space Needle. Note also that vertical exaggeration is enabled.]]

### 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
• SQL-Data of all scanned coordinates

### 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

File:WikiMiniAtlas KML screenshot.png
WikiMiniAtlas displaying the KML data attached to the Bridgwater and Taunton Canal article (blue line) and the Coordinate points from the article (blue dots).

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 (18px) 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 Template:Tl 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.

### WikiProject Geographical coordinates categories

<categorytree>WikiProject Geographical coordinates</categorytree>

### World map displaying the concentration of wikipoints

File:Imageworld-artphp3.png
Wikipedia-World allows generating such maps (see here)

Articles of interest
•  :Coordinate system, a system that uses numbers to uniquely determine position
•  :Geoinformation, created by manipulating geographic (or spatial) data (generally known by the abbreviation geodata) in a computerized system
•  :Geotagging, a process of adding geographical identification metadata to various media
•  :ISO 6709, standard representation of latitude, longitude and altitude for geographic point locations
•  :LOC record, a means for expressing geographic location information for a domain name
Wikipedia project pages of interest
• Categorization of location, proposal to generate lists of articles about nearby locations from a given Wikipedia article
• Coordinate-referenced map templates, inactive guideline proposal for using coordinate-referenced map templates to generate maps in Wikipedia articles
• Geographic references, a list of sources used in the creation of encyclopedia articles on various geographic topics and locations
• Geonotice, location targeted messages using geocoordiates to announce upcoming Wikipedia meetups and local events
• How to add geocodes to articles, a short guide to how to add geographic coordinate tags to Wikipedia articles
• How to add geocodes to articles by User:EncMstr, EncMstr's guide on how to enter coordinate data using Template:Tlx
• MoS Geographical coordinates, Official style guideline on geographical coordinates
• Mobile access, How to use a mobile phone to search for geotagged Wikipedia articles near your current location
• Obtaining geographic coordinates, listing various ways on how to obtain geographic coordinates for use in an article.
• Version_1.0_Editorial_Team/WPPlaces, Version 1.0 Editorial Team contact results with WikiProject Geographical coordinates
• WikiProject Maps/Source materials, list of free maps for use in creating geographical maps for Wikipedia.
Other
Templates