Wikipedia:WikiProject Geographical coordinates

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WP:GEO

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.

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] Parentage

The parent of this WikiProject is WikiProject Maps.

[edit] Descendant WikiProjects

No descendant WikiProjects have been defined.

[edit] Similar WikiProjects

Other WikiProjects that make use of geographical coordinates include:

[edit] Participants

[edit] Markup

The practical usage of this system for Wikipedia markup is described in the style guide for geographical coordinates.

In addition, a template for making ordinary text links to the maps is available through the coor family of templates.

[edit] Google-Maps-Tool for the determination of coordinates and markup-building

On GISWiki the Tool hjl_get_Coor has been developed, that takes the coordinates from a Google Map and builds the {{coor d|...}} or <geo>...</geo> markup.

There is a version for the english and german Wikipedia available.

[edit] Google-Earth-Tool for the determination of coordinates and markup-building

A tool with the same formular is here. There is a crosshair in the middle of the screen in Google Earth. Place the cross hair exactly over the place and click on it. Then follow the link to specification.

Please deactivate the tool if unused.

[edit] Google-Earth-Tool with the help of geonames.org

We have a database with 142.000 Entries. With a click on the city you get the geotag for the Wikipedia. http://www.alder-digital.de/wiki/index.php/Geonames_in_GoogleEarth_(en)

[edit] Goals

  1. Should provide a uniform markup and appearance for all geographic coordinates
  2. Markup should be easy and natural to use
  3. 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
  4. Clicking on the 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.
  5. 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).
  6. Serve as a tool for finding Wikipedia articles describing nearby locations. See also meta:Wikipediatlas.
  7. Adhere to existing Internet standards for geographic coordinates as far as possible

[edit] Examples

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:

San Francisco
Enlarge
San Francisco

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:

Mount Baker viewed in the direction of Seattle
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Mount Baker viewed in the direction of Seattle

[edit] Implementation details

[edit] Geo tag

To define a geographical point, the Mediawiki gis extension is required. For further information, see the Mediawiki documentation.

NOTE: This extension is available, but is currently not enabled for Wikipedia. The functionality is thus currently only available via the template:coor family, which is an interim solution, e.g.
On the surface of the earth, 1 minute of arc of latitude corresponds to 1.0 nautical mile or 1.852 kilometer, whereas, 1 arc second of latitude corresponds to 30.8667 meters (101.269 ft). Because of the numerical equivalence of minute of arc and nautical mile measures, many people find minutes, in degree-minute (dm) format easier to comprehend than arc seconds in degree-minute-second (dms) format, e.g., for navigation.

The geo tag specifies the coordinates as degrees/minutes/seconds of latitude and longitude, like this:

<geo>48 46 36 N 121 48 51 W</geo>.

In the finished article, the tag will appear as 48°46′36″N, 121°48′51″W. Seconds, or minutes and seconds, may be omitted. Optionally, the precision of the smallest unit used may be increased using decimals.

[edit] Parameters

Following the geographical coordinate, further parameters can optionally be supplied, separated by underscores. This will help in finding suitable map resources, and will become more important when the Wikimaps become fully functional.

[edit] type:T

Sets the type of this location, which will be used for the reverse mapping of the points. Will also set the default map scale. Types are:

country (e.g. "type:country") 1:10,000,000
state Where applicable 1:3,000,000
adm1st Administrative unit of country, 1st level (province, county) 1:1,000,000
adm2nd Administrative unit of country, 2nd level 1:300,000
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 1:100,000
isle 1:100,000
waterbody Bays, fjords, lakes, glaciers, inland seas... 1:100,000
landmark Cultural landmark, building of special interest, tourist attraction and other points of interest. 1:10,000

Sample:

[edit] scale:N

Sets the desired map scale as 1:N. This will override the default scale. The scale: prefix can be omitted.

[edit] region:R

Sets the preferred map region of coverage, used in selecting appropriate map resources for the area. 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:

Sample:

[edit] globe:G

Specifies other worlds than earth. Such as Moon.

[edit] The map source page

To generate the list of map sources, the Mediawiki gis extension is required. The definition of the map sources page is via Wikipedia:Map sources. For further information, see the Mediawiki documentation.

NOTE: This mechanism is available, but currently not enabled for Wikipedia, The current solution is running on an external server as a proof-of-concept, and is available via the template:coor family. The map source page produced is defined in the editable "Wikipedia:Map_sources" (sample currently at User:Magnus Manske/GeoTemplate). In the interim solution, the URL of the actual map sources page request is:

[edit] Templates

See Template talk:Coor dms for one practical way of entering geographical coordinates.

As of mid-2006, there are several different high-level ways of entering coordinates, with no clear consensus on the best way. The most popular techniques are:

  1. Template:coor dm and Template:coor dms. These are intended to be used in-line, along with prose text, e.g. "Mount Everest is at {{coor dms|27|59|16|N|86|56|40|E}}", which displays as "Mount Everest is at 27°59′16″N, 86°56′40″E"
  2. Template:Geolinks-US-cityscale, Template:Geolinks-US-streetscale, etc. These templates are intended to be used in an article's "External links" section. They expand to a selection of map or image server links (e.g. Google Maps, Terraserver, etc.). Currently, these templates also cause coordinate display near the page's title, as described below. See Template talk:Geolinks-US-streetscale for discussion.
  3. Template:coor title dm and Template:coor title dms. These may be placed anywhere in the article source text, and do not expand in-line; rather, they cause the coordinates to be displayed at the very top of the page, near the article's title, in a somewhat skin-dependent way. See Krasnoyarsk hydroelectric dam for an example. Placement of coordinates at the article top in this way is somewhat controversial; see Template talk:Coor title dms for discussion. (Placement of the template in the article source text is, by convention, at the bottom, along with categories and such, although this, too, is under some debate.)
  4. Infoboxes. Many infobox templates for geographic places have a field for specifying a place's coordinates. Typically, these templates make use of one of the lower-level templates already described, and may therefore also cause display in the title bar. See Template:Infobox City and Template:Infobox Mountain for examples (or for usage examples: Los Angeles and Mount Everest).

If creating new templates, it is important that they are defined using Template:coor. See Template:coor d for an example.

For assembling the two composite parameters of coor from given values or e.g. parameters of an infobox, it is convenient, and helps standardization, to use templates. Note however that parameter values of coor, like those of any template, cannot be expressed using templates. Therefore assembling the composite parameters of coor is not done separately by templates. Instead, the auxiliary templates like "coor dm" call coor themselves, with parameter values expressed in terms of the parameters of "coor dm". An infobox can call "coor dm" with parameters, which typically are partly passed on from some of the parameters of the infobox, while other parameters are fixed for that infobox, e.g. N and E for an infobox for the Netherlands, e.g. Template:Infobox Dutch municipality 3.

Where Ordnance Survey grid references are used as the coordinates, use (or create) a template which uses Template:oscoor.

[edit] How to obtain geographical coordinates

See Geographic coordinates (obtaining)

[edit] Geodetic system

All coordinates should be referenced to WGS84, or an equivalent datum.

[edit] Precision

Regardless of how coordinates are obtained, some thought should be given as to the precision used in a Wikipedia article. For example, if just giving the location of a city, precision greater than 100 meters is not needed unless specifying a particular point in the city, for example the central administrative building. Specific buildings or other objects of similar size would justify precisions down to 10 meters or even one meter in some cases. A general rule might be to avoid giving precisions greater than one tenth the size of the object described in the absence of a clear reason to do so.

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

  • One degree along a line of longitude is 111 km (~ 100 km)
  • One minute along a line of longitude is 1.85 km (~ 2 km)
  • One second along a line of longitude is 31 m (~ 30 m)
  • One tenth of a second along a line of longitude is 3.1 m (~ 3 m)


  • One tenth of a degree (one decimal place) is 11 km (~ 10 km)
  • One one-hundredth of a degree (two decimal places) is 1.1 km (~ 1 km)
  • One one-thousandth of a degree (three decimal places) is 110 m (~ 100 m)
  • One ten-thousandth of a degree (four decimal places) is 11 m (~ 10 m)
  • One hundred-thousandth of a degree (five decimal places) is 1.1 m (~ 1 m)

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.


[edit] Series of coordinates

[edit] Coordinates formatted through Template:Coor

Templates are listed in Category:Coordinates templates


[edit] Templates which use, or could use Template:oscoor

Templates creating links to online maps:

Infobox templates:

[edit] Articles with coordinates, but not linked to Template:Coor

/Various formats

Articles/infoboxes

  • Rambot articles
  • Lunar coordinates

Infoboxes in Templates

Articles with URL to Google Maps: http://en.wikipedia.org/wiki/Special:Search?search=maps.google.com&go=Go

[edit] See also

[edit] External links

[edit] References

[edit] Find coordinates of a place to add to Wikipedia

[edit] Convert between coordinate systems

[edit] Alternate schemes

  • World History Timeline - This web application allows anyone to create events in history and map them on both a timeline and map of the earth. Work for importing and linking wikipedia articles is in progress.
  • Placeopedia.com, a website based on Google maps which makes it easy to connect Wikipedia articles to places. The data is then provided in a free, syndicated feed in a variety of formats for the Wikipedians to do what they want with.

[edit] View Wikipedia in Google Earth

  • Webkuehn.de, provides a huge database for download, to be used in Google Earth
  • Alder-Digital.de, provides access to the same data with a server version which only downloads the data needed for the current view shown in Google Earth

[edit] Visualization of Wikipedia articles with Google Maps

  • PINTOMAP searches the whole Wikipedia-Database for coordinates and visualizes them on a Google-Map.
  • www.geonames.org over 140,000 Wikipedia articles in 185 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
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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 lables with links other geocoded articles are placed on the map to allow spatial browsing of wikipedia. The newes update adds a satellite image mode (using Landsat7 data) and more zoomlevels down to a resolution <100m.

[edit] All geodata in CSV file format


[edit] Wiki pages containing coor or a related template

Coor - Degrees - Degrees & Minutes - Degrees, Minutes & Seconds

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