Wikipedia:Obtaining geographic coordinates: Difference between revisions
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| Calculators || Conversion || Many scientific calculators (including the one that comes with Windows, use dms and inv dms) can convert coordinates. |
| Calculators || Conversion || Many scientific calculators (including the one that comes with Windows, use dms and inv dms) can convert coordinates. |
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||http://gps-points-of-interest.com/ |
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| Web http://gps-points-of-interest.com/ page you can find the geographic coordinates of towns and villages around the world |
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| [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. |
| [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. |
Revision as of 14:45, 13 March 2014
This is an information page. It is not an encyclopedic article, nor one of Wikipedia's policies or guidelines; rather, its purpose is to explain certain aspects of Wikipedia's norms, customs, technicalities, or practices. It may reflect differing levels of consensus and vetting. |
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.
Manually
- Using a GPS receiver with a clear view of the sky.
- Looking at a printed map or atlas, either those you own or at a library.
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. |
Public domain databases
- U.S. Board on Geographic Names – The United States Geological Survey public domain GNIS database contains a huge list of locations in the United States. It can be found on the Web at geonames
.usgs .gov. Most of these coordinates use the NAD83 map datum, which is sufficiently close to WGS84 for use. - US Census TIGER
- US Census Boundary and Annexation Survey
On the web
Wikipedia compatible geotagging metadata generators
List of services, directly providing Wikipedia/Wikimedia Commons compatible geotagging metadata.
Currently preferred geotagging templates are:
{{coord...}}
for English Wikipedia and
{{location...}}
or
{{location dec..}}
for Wikimedia Commons.
Tool | Type | Metadata types | Coordinate parameters | Description | Licensing |
---|---|---|---|---|---|
GeoLocator (project page) |
Google Maps based | {{coord}} , {{location}} , {{location dec}} , microformats, custom editable template
|
type, scale, region, heading | Coordinate picker and online metadata authoring tool. Features: visual heading (camera direction) picker, GeoTemplate/GeoHack compatibility, flexible coordinate parser, URL integration, configurable degree/arcsec precision. Metadata roundtrip support – pasting of existing geotag, updating its location or parameters and encoding new one. |
Generic web based services
These services are web based, and provide on-line methods for obtaining co-ordinates.
Be sure to read the licensing information carefully so that data providers receive an appropriate attribution.
Tool | Type | Description | Licensing |
---|---|---|---|
GISWiki | Google Maps tool | The hjl_get_Coor tool has been developed, which takes the coordinates from a Google Map and builds the {{coord...}} or <geo>...</geo> markup.There is a version for the English Wikipedia available. |
? |
EarthTools | Global browser | Designed to give coordinates for places, sunrise and sunset times, local time zones elevation/height above sea level. It's extremely easy to use and has a very nice interface (takes Google Maps and adds more functions to it). | ? |
3maps | Maps | Allows you to paste the URL from many popular online mapping tools and get the current place and coordinates. Can search coordinates from a raw paragraph of text. The smart address search. | ? |
NASA World Wind | NASA World Wind | Open source 3D interactive world viewer. See also: Spoon.net for online version | NOSA |
Bing Maps | Maps | Provides geographical coordinates of a location when a "Pushpin" has been created.
|
Proprietary EULA |
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. | Arieal imagery provided is from Google Earth Terms of use |
Calculators | Conversion | Many scientific calculators (including the one that comes with Windows, use dms and inv dms) can convert coordinates. | http://gps-points-of-interest.com/ |
Web http://gps-points-of-interest.com/ page you can find the geographic coordinates of towns and villages around the world | |||
The Getty Thesaurus of Geographic Names | Name search | Allows you to find coordinates with a place name search. | [1] |
World Gazetteer | Name search | Provides geographic coordinates of many cities (select country – "cities" – city) | [2] |
Geonet Names Server (GNS) | Name search | U.S. National Geospatial-Intelligence Agency (NGA) maintains a comprehensive database of non-U.S. place data. | |
The Libre Map Project | The purpose of the project is to aggregate and make digital maps and related GIS data available for free. | CC-BY-SA 2.0 | |
Microsoft Research Maps | Global browser | Free online repository of public domain aerial imagery and topographic maps provided by the U.S. Geological Survey (USGS). | |
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. | |
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. | [3] |
Geocoder.us | Address search | Look up the coordinates of any location in the United States by its address or nearby intersection. Only works for US addresses. | [4] |
Great Circle Mapper | Name search | Has geographic coordinates for airports, heliports, and other facilities which have an IATA or ICAO code. You can also search by location name. | |
JRC Fuzzy Gazetteer | Fuzzy name search | Spelling tolerant place name gazetteer, mostly based on GSN data, enriched with data collected from United Nations missions and European Commission services. | |
Plexscape WS | Google Maps tool – Coordinate converter | Online application to acquire coordinates for any place on Earth.
|
Coordinates also can be found in other sources, such as:
- Looking at a website built by GPS users, e.g., geourl
.org, www .findu .com or www .geocaching .com - Looking for GPS "Waypoint" files
- Looking at a wiki that uses map coordinates, e.g., susning
.nu
Google tools
- 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.
- Another method is using the LatLng ToolTip from Google Maps. This feature is activated through Google Labs by entering its Google Maps Labs section here. The Tool Tip will display a box with coordinates that move as the mouse cursor is moved. Note that the upper left corner of the tooltip box actually becomes the precise point of the cursor whose coordinates are displayed in the box. There is also a related LatLng Marker tool which is useful because it makes it easy to copy and paste the coordinates.
- 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. "http://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. Based on Google Maps API and geocoder, this page simplifies the task by displaying directly the coordinates, including in one of Wikipedia formats (for English and French Wikipedias), and allowing quick finding of places either by moving the map or typing in postal addresses or place names. Informal research indicates that coordinates obtained in this way usually agree with precisely determined WGS84 coordinates to within about ten meters, or four decimal places in decimal degree notation.
- Copying the coordinates from the URL can be made easier with a Javascript-supporting browser, by adding the following bookmarklet (create a new bookmark with this code as the URL):
Centre the map on the point as previously, and then open the newly created bookmark. A coordinate template text will appear, ready to be pasted to Wikipedia. Alternatively, to format the coordinates directly into the template code for articles, with display next to the title, use the following code as a bookmarklet:javascript:void(prompt('',"{{coord|" + gApplication.getMap().getCenter().lat() + "|" + gApplication.getMap().getCenter().lng() + "}}"));
- Caution: a previous version of this code was faulty. If you installed this Bookmarklet before June 15. 2009 please update it with the current version..
javascript:coord=[gApplication.getMap().getCenter().lat(),gApplication.getMap().getCenter().lng()];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));
- Googling for the city name together with "latitude", "longitude", which will give hits like http://www.infoplease.com/ipa/A0001769.html
- Google Earth makes it easy to search for the coordinates of any location and zooming in on them. There are many ways to obtain coordinates:
- Move the mouse cursor to where you want, and note the coordinates displayed in the lower left-hand corner of the earth display window. The display format can be changed in the Options. 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.
- Google Earth 4.1 and newer can make a Google Maps URL, from which you can copy the latitude and longitude in decimal format as mentioned above. Just center the screen on your location by double-clicking on it, and then use the "View in Google Maps" button at the top.
- Create a placemark (probably in the "Temporary Places" folder). Right-click or control-click on the placemark; one of the options is "Copy". Copy the placemark and paste it back to a text editor. The result is a KML ("Keyhole Markup Language") description of the placemark, and 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 reversed from the lat/long you were expecting; you have to swap them when you extract them. 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: 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 Picasa application allows seamless integration with Google Earth to tag sets of images saved on the computer. Select the images to tag on Picasa, and then choose "Tools / Geotag / Geotag With Google Earth". Google Earth opens with first of the chosen images in the bottom right corner, and a crosshair in the middle of the screen. Move the view so that the crosshair is on top of the desired location, and click on the Geotag button. A placemark will be added to your Temporary Places folder, from where you can normally copy it in kml format as explained above. Clicking Done will return to Picasa, which can export the data in kmz at any later date.[5] [6]
- The exported kml or kmz file can also be converted to templates using the kmlconvert tool.
- Various Google-based tools can be used to find latitude and longitude coordinates, such as the following: [7], [8], and [9].
OpenStreetMap
OpenStreetMap can be used; simply navigate to the desired point by double-clicking on it, select the "share" icon from the top-left toolbar, copy the "link" URL (N.B. not the shortlink) and extract the coordinate values from it.
For example, http://www.openstreetmap.org/?lat=52.54341&lon=-1.91035&zoom=15&layers=M includes a latitude of 52.54341 and a longitude of -1.91035.
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"
Within Wikipedia
- Category:Lists of coordinates
- CatScan in the example with buildings in New York City with or without Coordinates.
Specific countries/places
- PlaceNames provides coordinates for locations and landmarks in the United States.
- For US coordinates, the USGS GNIS service is extremely extensive. It also provides linkouts to topozone and terraserver so that you can tweak the results to your liking.
- For US addresses, A2B provides you with the latitude and longitude of a US street address and returns nearest websites to that address. You can then add your own sites.
- Find Longitude and Latitude coordinates by US Zip Code
- For placenames in Antarctica, try Geographic Names Information System, Antarctica
- For Australian placenames, try Geoscience Australia Place Name Search
- For Canadian places Canadian Geographical Names Data Base (CGNDB) Querying Canadian Geographical Names
- For UK places, 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.
- UK places and Irish places traditionally use grid references, and a latitude /longitude system tied to an OSGB36 datum. This gives a 112m difference. OStoWiki Tool will translate data from Commons tags, or Grid References into Wikipedia tags. Wikipedia's own output from GeoHack is broken: it does not take the different datum into account, and therefore returns Grid References which are wrong by about 100m. Note that List of United Kingdom locations already has coordinates and grid references for many places.
- Display UK Longitude and Latitude
Add to article
Finally, add the coordinates to the relevant article:
To add 57°18′22″N 4°27′32″W / 57.30611°N 4.45889°W 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 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
orcity(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.