WP:Obtaining geographic coordinates
{{infopage|WP:OGC}}
This page lists ways to obtain and add geographic coordinates to articles.
=Obtaining=
There are various ways to obtain geographic coordinates. Note that regardless of the source of coordinates, it is a good practice to evaluate whether they appear reasonable at first glance.
From maps
=From printed maps=
Looking at a printed map or atlas, either those you own or at a library.
{{notice|Printed maps display coordinates plotted to the datum selected by the mapmakers. In the UK (which uses OSGB36), Ireland, France and Germany, these datum will not be the coordinates used in Wikipedia (WGS84) thus leading to differences of over 100m. See geographic coordinate system for more information. For country specific systems, such as the UK OS grid references, see here.}}
=From online maps=
==Google Maps==
[http://maps.google.com/ Google Maps] can be used to find coordinates 3 different ways, although many other sites make use of Google imagery with specialist overlays.
- The simplest way to get coordinates from Google Maps is to right-click on the desired location and click "What's here?". The coordinates are now shown in the search box.
- Coordinates can also be extracted from generated links with the following procedure. First locate the place you require coordinates for, and double click on it to centre the map around that point. Then click "Link" at the top of the map, and the coordinates (in degrees and parts of a degree in decimals) appear in the address bar, e.g. "https://maps.google.co.uk/?ll=51.455558,-2.605047&spn=0.032304,0.069523". In this case the latitude is 51.455558, and the longitude is -2.605047. The reverse is possible by entering the lat and long into the search bar, with a space between them.
- Copying the coordinates from the URL can be made easier with a Javascript-supporting browser, by adding any of the following bookmarklets (create a new bookmark with this code as the URL):
- There is a [https://github.com/rottina/wiki-coords wiki-coords] bookmarklet, maintained in GitHub.
- The following bookmarklet will create an output such as
:{{coord|51.5030515|-0.1281352}} javascript: (function () { var matches = location.toString().match("\/maps\/.*@([0-9.-]+),([0-9.-]+)"); prompt('',"{{coord|" + matches[1] + "|" + matches[2] + "}}"); }()); - The following bookmarklet will create an output such as
:{{coord|51|30|10.99|N|0|07|41.29|W|display=title}} javascript:var matches = location.toString().match("\/maps\/.*@([0-9.-]+),([0-9.-]+)");coord=[matches[1],matches[2]];output='{{coord|';for(x in [0,1]){neg=(coord[x]<0);coord[x]=Math.abs(coord[x]);deg=Math.floor(coord[x]);minr=(coord[x]-deg)*60;min=Math.floor(minr);sec=Math.floor((minr - min)*60*100000)/100000;output+=deg+"|"+(min<10?'0':)+min+"|"+(sec<10?'0':)+sec.toFixed(2)+'|'+(x==0?(neg?'S|':'N|'):(neg?'W|':'E|')+"display=title}}");};void(prompt('Coordinates for Wikipedia',output));
: To use these bookmarklets, centre the map on the desired point and then open the newly created bookmark. A coordinate template text will appear, ready to be pasted to Wikipedia.
== Wikipedia compatible geotagging metadata generators ==
List of services, directly providing Wikipedia/Wikimedia Commons compatible geotagging metadata.
Currently preferred geotagging templates are:
for English Wikipedia and
or
for Wikimedia Commons.
class="wikitable sortable"
! Tool ! Type ! Metadata types ! class="unsortable" | Description ! Licensing |
[http://tools.freeside.sk/geolocator/geolocator.html GeoLocator] (project page) |Google Maps based | |type, scale, region, heading |Coordinate picker and online metadata authoring tool. | |
[https://tools.wmflabs.org/locator/coordinates.php Coordinates tool]
|Google Maps based | |type, scale, region |Coordinate picker and online metadata authoring tool. | |
== Generic web-based services ==
These services are web based, and provide online methods for obtaining coordinates.
Be sure to read the licensing information carefully so that data providers receive an appropriate
attribution.
class="wikitable sortable"
! Tool ! Type ! class="unsortable" | Description ! Licensing | |||
[https://getlatlong.net/ Getlatlong] | Map to coordinates | Move a marker on a Google Maps map (map or satellite view) and get Latitude, Longitude for the location. User interface in English language. | |
[http://www.mapcoordinates.net/ Mapcoordinates] | Map to coordinates | Move a marker on a Google Maps map (map or satellite view) and get Latitude, Longitude and Elevation for the location. User interface in German language. | |
[https://worldwind.arc.nasa.gov/ NASA World Wind] | Maps | Open source 3D interactive world viewer. See also: [http://explorer.worldwind.earth/ online version]
Licensing: NOSA | |
[http://www.bing.com/maps/ Bing Maps] | Maps | Provides geographical coordinates of a location when a "Pushpin" has been created.
Licensing: Proprietary EULA | |
[http://www.wikimapia.org/ WikiMapia] | Global browser | The latitude and longitude of the crosshairs are given at the bottom left of the screen and are constantly updated as the map is moved. Clicking on them will bring up a dialog box from which they can be copied in decimal or deg/min/sec form.
Licensing: Arieal imagery provided is from Google Earth [http://www.google.com/intl/en_ALL/help/terms_maps.html Terms of use] and one can switch to Bing Maps and OpenStreetMap as needed | |
Calculators | Conversion | Many scientific calculators (including the one that comes with Windows, use dms and inv dms) can convert coordinates. | |
[http://www.getty.edu/research/tools/vocabularies/tgn/index.html The Getty Thesaurus of Geographic Names] | Name search | Allows you to find coordinates with a place name search.
Licensing: [http://www.getty.edu/legal/copyright.html] | |
[http://geonames.nga.mil/gns/html/ Geonet Names Server (GNS)] | Name search | U.S. [http://www.nga.mil/ National Geospatial-Intelligence Agency (NGA)] maintains a comprehensive database of non-U.S. place data. | |
[http://libremap.org/ The Libre Map Project] | The purpose of the project is to aggregate and make digital maps and related GIS data available for free.
Licensing: CC-BY-SA 2.0 | ||
[http://www.gpsies.com/coordinate.do GPSies.com] | Google Maps tool | Gives coordinates for places, names, elevation/height above sea level on Google Maps (reverse geocoding). You can download the coordinate as GPX Waypoint, PCX5 Waypoint, LOC Geocache or Google Earth KML. | |
[http://www.geocodefarm.com GeocodeFarm] | Address & coordinate search | Look up address by coordinates or coordinates by address. Forward and Reverse Geocoding Service. Web Form or API Available. API is free for 2,500 queries per day, more are paid. Web Form is free for unlimited queries. International Coverage in most countries.
Licensing: [http://geocodefarm.com/policies/terms-of-service/] | |
[http://gc.kls2.com/ Great Circle Mapper] | Name search | Has geographic coordinates for airports, heliports, and other facilities which have an IATA or ICAO code. You can also [http://gc.kls2.com/cgi-bin/gclookup search by location name]. | |
[http://ws.plexscape.com/Services/CoordSysWS/Pages/Transformations.aspx Plexscape WS] | Google Maps tool – Coordinate converter | Online application to acquire coordinates for any place on Earth.
|
==Google Earth==
Google Earth makes it easy to search for the coordinates of any location and zooming in on them. The coordinate format can be chosen via Tools → Options → 3D View → Show Lat/Long
. There are many ways to obtain coordinates:
- Move the mouse pointer to where you want, then use the keyboard to select the Menu item
Edit → Copy View Location
to copy the coordinates to the clipboard. More convenient is the associated keyboard shortcut. If it is not provided in the currently chosen language of Google Earth, change it toEnglish (UK)
(Tools → Options → General → Language settings
). - Move the mouse pointer to where you want, and note the coordinates displayed on the bottom of the earth display window. The numbers will have to be written from the screen manually, but this does let you choose an appropriately rounded value, without excess precision, for the location you're capturing.
- Center the screen on your location by double-clicking on it, then use the
View in Google Maps
button at the top (Google Earth 4.1 and newer). This will open Google Maps within Google Earth. You can see the center coordinates in decimal format in the address bar, but unfortunately you cannot copy them directly. To do so, use the buttonOpen this page in your default web browser
to display the same Google Maps page in your browser with unrestricted access to its address bar. Of course, all the methods listed above for Google Maps are also available. - Center the screen on your location by double-clicking on it, then create a placemark (
Add Placemark
-button or MenuAdd → Placemark
. The "New Placemark" window displays the coordinates. - For the coordinates of an existing placemark, right click on it on the sidebar and select "Copy". This makes the clipboard hold a KML ("Keyhole Markup Language") description of the placemark. Since KML is XML, it's easily manipulable. Towards the bottom of the placemark is a tag
<coordinates>...</coordinates>
which contains the long/lat coordinates in decimal degrees. Note that the order of the coordinates is lon/lat; you may want to swap the both in order to get the more common lat/lon notation. Also note that the precision is ridiculously high; you'll probably want to trim it down. - Install the Google Earth version of the hjl_get_Coor tool: [http://www.alder-digital.de/wiki/images/Ald-Hjl-Koord-en.kmz Ald-Hjl-Koord-en.kmz]. Once it's installed, a crosshair icon appears in the middle of the Google Earth screen. Move the view so that the crosshair is on your desired location, and then click on it. There is a link to the hjl_get_Coor tool, which gives the coordinates back in your chosen wiki markup that can be copied and pasted to an article.
- The exported kml or kmz file can also be converted to templates using the [http://tools.wikimedia.de/~para/GeoCommons/kmlconvert.php kmlconvert] tool.
==OpenStreetMap==
OpenStreetMap can be used. For convenience, close any open sidebar (to allow a simpler URL format like the one below). Simply navigate to the desired point by right-clicking on it, then select the "Centre map here" option from the dialog. Finally, extract the coordinate values from the browser URL (N.B. not the shortlink).
For example,
includes a latitude of 10.79375
and a longitude of 122.00671
.
A quicker alternative to extract coordinates is to right click on a desired point in the map and select "Show address". From the sidebar search results, copy the coordinates (in latitude, longitude
format).
==World Wind==
NASA World Wind can access a large online database of U.S. and global placenames (cities, villages and other geographic & anthropogenic features). Street addresses can be found using Yahoo and Virtual Earth geocoders (works for the US, Australia, UK, Japan... and maybe some other countries). (Offline search requires this pack http://www.worldwindcentral.com/wiki/Add-on:Classic_Placenames_cache_pack) Press Ctrl-F, enter the official place name, click Search, you will probably find the place you're looking for. Click Go. (of course you can navigate to the desired spot with your mouse; select View->Show Position to see the coordinates) Press Ctrl-C to copy the decimal coordinates. Paste it into Wikipedia. Example: For Tucson International Airport → worldwind://goto/world=Earth&lat=32.11611&lon=-110.94109&alt=24389"
From directories/databases
=For the US=
- The United States Geological Survey's public domain Geographical Names Information Service [http://geonames.usgs.gov/pls/gnispublic/ database service] is extremely extensive, although riddled with errors. It also provides linkouts to topozone and terraserver so that you can tweak the results to your liking. Most of these coordinates use
- US Census TIGER
- US Census [http://www.census.gov/geo/partnerships/bas.html Boundary and Annexation Survey]
- [http://www.hmmm.ip3.co.uk/longitude-latitude/us-zipcode.shtml Find Longitude and Latitude coordinates by US Zip Code]
- [https://gpscoordinates.info/ Search engine for GPS coordinates of latitude and longitude of the United States of America]
=For other regions=
- For placenames in Antarctica, try [http://geonames.usgs.gov/antform.html Geographic Names Information System, Antarctica]
- For placenames in Australia, try [http://www.ga.gov.au/map/names/ Geoscience Australia Place Name Search]
- For placenames in Canada, try the Canadian Geographical Names Data Base (CGNDB) [http://www.nrcan.gc.ca/earth-sciences/geography/place-names/search/9170 Querying Canadian Geographical Names]
- For placenames in the UK, [http://www.streetmap.co.uk Streetmap.co.uk] is very useful for clicking on a precise point to show the coordinates. Near the foot of a page displaying a map is a link "Click here to convert/measure coordinates" which takes you to a "Grid Conversion Results" page with the WGS84 latitude and longitude amongst other useful values.
From other sources
- Using a GPS receiver with a clear view of the sky.
- Looking for "Waypoint" files on sites for GPS users, e.g.
- [http://www.geocaching.com/ Geocaching.com]
- [https://www.outdooractive.com/en/tours/#cat=Hiking&wt=Glasgow%20City%20(United%20Kingdom)&zc=12,-4.30201,55.95401 Outdooractive.com]
- [http://www.findu.com/ Findu.com]
- Googling for a city name together with "latitude", "longitude" will usually yield a plethora of useful results ([https://www.google.com/search?q=Glasgow+latitude example])
- Wikidata has geocoordinates for many objects
=Formats and formatting=
- UK places and Irish places traditionally use grid references, and a latitude /longitude system tied to an OSGB36 datum. This gives a {{convert|112|m|abbr=on}} difference.
- The NAD83 map datum is sufficiently close to WGS84 for initial use. It is best to double check on a mapping site such as WikiMapia.
- Cordinates obtained in China from commercial sources (Google, Bing, Baidu, etc.) may be obfuscated with GCJ-02 or BD-09. Vector sources are more frequently affected than satellite sources. Use this gadget to obtain deobfuscated coordinates, then double check on OpenStreetMap.
=Add to article=
Finally, add the coordinates to the relevant article:
{{Coord how-to}}
= See also =