Commons:Geocoding - Wikimedia Commons

Commons:Geocoding - Wikimedia Commons
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On Wikimedia Commons,
geocoding
is the practice of attaching geographic location information to media. When we geocode media on Commons we identify the latitude and longitude from
where the media was recorded
and attach it to the description page using a
{{Location}}
template. For jpeg images, geodata can also be stored in the image
Exif
Geocoded images on a
worldmap
As of February 2015, 5.2M Wikimedia Commons images are geolocated.
Media that is geocoded can be found in
Category:Media with locations
You can find coordinates for untagged pictures in:
Category:Location possible
. If you see an image that needs geotags, you can add
{{Location possible}}
Geocoding media on Commons
Geocoding is easy and only takes a couple of steps. All coordinates should be referenced to the
en:WGS84
datum, the one supported by GPS systems and Google Maps. References taken from printed maps are unlikely to use this datum, and lead to inaccuracies in the order of hundreds of metres. National Grid reference systems use a local datum so will provide the wrong result.
On Commons we record
the location of the camera
as accurately as we can. Pictures can be geocoded in the camera, or in your own computer, or after uploading. Some of the tools can be activated in the "gadget" tab of
Special:Preferences
Geocoding tools
: Adds three
geocoding
links to the toolbox:
recent changes
daily error log
, and
talk
Geocoding To Do
: Add a tab to the category linking to the
tool
allowing to view images that are not
geocoded
talk
Automatic procedures
GPS or other automated methods can be especially useful in rural locations without landmarks which can be easily recognized in the aerial images. If your camera has a built-in
GPS receiver
(as most smartphone camera phones do) then your work is already done. Since November 2011, the Upload Wizard adds the proper Geocoding Templates from the GPS data stored in your images. For pictures not uploaded through the Wizard,
{{GPS EXIF}}
can be added to summon a bot to code them.
You can also use a separate GPS receiver to record the location while you are recording the media, and use computer software to merge the locations into the image files. Such software uses the camera time tag in the image file to look up the coordinates from the GPS. For accurate results, the camera time must be correct or the time error entered manually. The time error can be monitored by photographing the time displayed by the GPS. Errors caused by spotty GPS coverage can be adjusted by the same tools that are used for manual geocoding, though more easily since you already have an approximate position.
By 2020 many cameras had a feature whereby they can connect to a smartphone via Wi-Fi or Bluetooth. The phone can control the camera remotely, transfer pictures from the camera, or transfer geocoordinates to the camera for insertion in the EXIF data of the picture. Some can only add coordinates after the fact, using a GPS log feature, and some can do it on the fly.
Adding Geotags before uploading
Some software, such as
Microsoft Pro Photo Tools
or
darktable
, allow you to add geographical information to images from a map. The upload wizard will also recognize these tags. These programs cannot add camera directions, but other programs such as
Geosetter
can insert metadata including: geographic coordinates of the location shooting, camera direction, and the name of the exact location.
If your camera has accidentally tagged your images with completely wrong geodata, you can remove them on a batch of pictures by using
ExifToolGUI
. It uses ExifTool that is also installed by Geosetter mentioned above.
Locator-tool
The
Commons:Locator-tool
allows to quickly add
{{Location}}
{{Object location}}
information to already uploaded images. You can specify a list of images to geocode (e.g., by querying a category), select their respective location on a map and let the
{{Location}}
be added/updated automatically.
Manual procedures
Zoom levels
OSM
scale
19
unavailable
18
1000
17
3000
16
5000
15
10000
14
30000
13
50000
12
100000
11
300000
10
500000
1000000
2000000
3000000
5000000
10000000
30000000
50000000
The easiest way to identify the location in urban areas is to use an online mapping site with aerial imaging such as:
GeoLocator tool
project page
Steps to obtain coordinates and build appropriate location tag:
find your location on embedded map (move/zoom/search it as needed)
place location marker on most exact location ([Alt+click] over your location, or by dragging a marker)
define
heading
(camera view direction) from that location ([Shift+mouse move]/[Shift+click])
copy resulting
{{location}}
markup
Steps to update an existing location tag (to improve location or to add heading):
paste existing location tag into query box and press Apply. Tag gets parsed and location will appear on a map.
update location marker to more exact location (by dragging it or by [Alt+click] over new location)
define
heading
(camera view direction) from that location ([Shift+mouse move]/[Shift+click])
copy resulting
{{location}}
markup back
Bing Maps
Right click where the exact location is and you have the coordinates. Paste into the Location template.
OpenStreetMap
Open a new browser tab/window and load
Search for the correct location; you probably want to zoom in to make this easier.
Right-click on the exact location the media was recorded. A little pop-up menu opens there. From the pop-up menu, select
Show address
Google Maps
Open a new browser tab/window and load
Search for the correct location (zoom in, Satellite mode is suggested).
Right-click on the exact location the media was recorded and select
Center map here
Click the link icon in the left sidebar
Copy the link in the top box (do not click
short url
Use the
Coordinate conversion helper
to insert the coordinates on the image page (add a heading such as "N","SE","NNW")
Check the page for instructions on installing and using it.
Google Earth
If you have
Google Earth
, a tool for geotagging can be installed:
Ald-Hjl-Koord-en.kmz
. A crosshair will appear in the middle of the Google Earth screen. Place the crosshair exactly over the camera location by moving the view, and click on it. The location template can be copied from the window that opens. (Please deactivate the tool if unused.)
If you have coordinates in a
KML
file (such as created in Google Earth and exported with "Save As" or "Copy", or aided by
Picasa
), the
kmlconvert
tool can be used to convert the coordinates to Commons templates. This method is suitable for geocoding a series of images.
See
en:Wikipedia:Obtaining geographic coordinates
for more information.
Adding a location template
The use of the following templates is encouraged:
{{Location}}
for camera locations
{{Object location}}
same idea for
object
instead of
camera
locations
Do not simply invent your own new templates or copy geocoding templates from other wikis without discussion. Doing so can break the automation that reads and uses the geocoding. Commons geocoding needs are also not the same as those of other projects.
Note that you also should not create your own wrappers around
{{Location}}
or
{{Object location}}
; this will break the automation as well. Just call one of the templates directly from the image description page.
Simply add
{{Location|lat|long}}
to the image page, filling in the lat and long from the procedure above. If the image page has an
{{Information}}
template, or similar, the
{{Location}}
template should come immediately after it. For example, the result for
{{Location|37.51136|-77.602615}}
will look like this:
Camera location
37° 30′ 40.9″ N, 77° 36′ 09.41″ W
View all coordinates using:
OpenStreetMap
Alternatively, to use degrees, minutes and seconds instead of decimal degrees, add
{{location|lat deg|lat min|lat sec|NS|long deg|long min|long sec|EW}}
to the image page, filling in the lat and long. For example, the result for
{{Location|37|30|40.9|N|77|36|9.41|W}}
will look like this:
Camera location
37° 30′ 40.9″ N, 77° 36′ 09.41″ W
View all coordinates using:
OpenStreetMap
Compass points
Parameters
Main galleries:
Template:Location#Template parameters
and
Template:Object location#Template parameters
Wikipedia geocoding often uses
parameters
after the coordinates to give more information about the location, but some of them are not useful here.
type
and
scale
- The defaults are
type:landmark_scale:5000
. See
above
for other values of
scale
, and the corresponding initial
OSM
zoom when opened via
GeoHack
. An explicitly given
scale
trumps an implicit
scale
value associated with an also given
type
TBD: list of
type
values and their corresponding
scale
defaults for commons, dewiki, and enwiki for comparison.
dim
- The
dim
in meters can be used for bigger areas in {{
object location
}}, e.g.,
type:mountain_dim:2000_scale:10000_region:PL-MA
TBD: document the effect (if any) of
dim
region
- If given the region
MUST
be an
ISO 3166-2
code, e.g., US-CA for
California
. The
region
can be used for the
GeoHack
selection of regional map services.
heading
- Used to indicate the direction the camera was pointing at. It is given as degree values
0-360
(clockwise with north as 0) or a compass point abbreviation as defined in
w:Boxing the compass
. (Example:
heading:NW
) Compass overlay can be displayed on Google Maps or in Google Earth to help find the correct heading, and the
GeoLocator
tool allows interactive picking of correct heading on a map as part of metadata authoring.
Precision
At the moment the named parameter
prec=1000
(example) in
{{Location}}
or
{{Object location}}
is only used to truncate the displayed coordinates on the page (category, file, or gallery.) The
GeoHack
map service still gets the full coordinates as specified without indication of the desired precision. The effect depends on the position (see below) and on the display style (decimal
ddd.nnnnnn
vs.
ddd°mm′ss.nnn″
), e.g.,
prec=1000
removes the
ss.nnn″
(seconds) display everywhere on earth, while
prec=100
only removes
.nnn
(decimal fractions of seconds.)
The linear measurement of a longitudinal angle varies according to latitude. If we are aiming to a precision of about 0.5–1 m, then it is appropriate to use decimal degrees with 5 decimal places. For the minute/second format, seconds with 1 decimal place will similarly give precision of about 1.5–3 meters of real earth surface. More decimal places have not sense because available maps and navigations are not more precise.
Length equivalent of longitudinal degree at selected latitudes in km
Latitude
Town
Degree °
Minute ′
Second ″
Decimal Degree at 4 dp
60
Saint Petersburg
55.65 km
0.927 km
15.42 m
5.56 m
51° 28′ 38″ N
Greenwich
69.29 km
1.155 km
19.24 m
6.93 m
45
Bordeaux
78.7 km
1.31 km
21.86 m
7.87 m
30
New Orleans
96.39 km
1.61 km
26.77 m
9.63 m
Quito
111.3 km
1.855 km
30.92 m
11.13 m
Note that latitudinal degrees do not vary significantly across the Earth, having a surface precision of 1" = 31 m or 0.0001° = 11 m. See
en:Geographic coordinate system
for more information.
Stats
For actual number of geocoded files, see
category:Media with locations
Geocoded images on Commons, March 2007 - mid 2010
Geolocated images in Wikimedia Commons 2012-01-21
Geolocated images in Wikimedia Commons 2014-02-21
Geolocated images in Wikimedia Commons 2015-01-07
Geocoded images on Commons, March 2007 - mid 2015
(See
File_talk:Commons_geocoding_graph.svg
for numbers)
Use of the information
Clicking on the coordinates on an image page will lead to a list of various services that can show the location. It is also possible to browse Commons images on a map:
Geocoded images from Commons plotted in OSM per
WikiMap tool
(lat/lon/zoom parameters or
whole cat
possible).
WikiShootMe
shows maps of photos and Commons objects that have or lack a photo.
A mini world map with thumbnails of geocoded images can be found from
WikiMiniAtlas on Commons
Some geocoded images from Commons plotted in
Open Street Map
(images tagged with
{{Object location}}
are not displayed).
Some geocoded images from Commons plotted in
Google Maps
(images tagged with
{{Object location}}
are not displayed).
– this service is no longer available
KML-file of some geocoded images from Commons for use in Google Earth:
GeoCommons
(images tagged with
{{Object location}}
are not displayed).
In the "gadget" tab of
Special:Preferences
, there is an option "View category on Google maps". If enabled, this adds a link "map" to all categories. This shows the location of geocoded images in the category on Google maps.
Adding
{{Geogroup}}
to a category page adds links to view the images in the category with various maps.
Warnings:
Services displaying the tagged images (categories, articles etc.) in the map have frequent link failures. Try to click a little later.
Indexing of the database is often delayed. A new image can appear in the map almost immediately, or after several days or even several weeks or months.
The number of image-icons displayed in the linked maps is very limited, i.e. the map can display only some of the geocoded images from the displayed area. To display more images of a specific place, you can zoom in or shift to a less crowded area.
At OpenStreetmap, icons with identical or nearby coordinates cover one another; only the top one is available to be clicked.
Tools providing map outputs:
Geocommons
– creates KML of location templates on Wikimedia Commons, managed by
Para
WIWOSM
– displays geometric objects from OpenStreetMap for Wikipedia/Commons articles, managed by
Simon04
Retsam
Kolossos
Things to do
Add geocoding to any location related media on Commons. Areas you know personally are easiest, but geocoding images from other areas based on satellite data and other photos is also possible. For help in finding material to work on, choose an interesting category and enter the name in
this tool
to see a gallery of images that need to be geocoded.
Find coordinates for pictures tagged with
{{Location possible}}
in:
Category:Location possible
Refine inaccurate geocoding on images that are off the correct camera location, or have been positioned in the exact same place as a number of other images (see
list
Monitor and fix tags of images with incorrect geocoding in
Category:Media with erroneous locations
and recently geocoded images (
gallery
).
Find coordinates with unknown headings and try to fix them (see
list
).
Verify or fix coordinates of images imported from external sources where geocoding may be less conscientious (see for example
Flickr images
Add camera heading for the images which contain coordinates without it.
Participants
Giovanni Ussi
Gmaxwell
evrik
Dschwen
Kolossos
Arcy
para
Wsiegmund
EugeneZelenko
VanHelsing.16
Qyd
bdesham
Simonizer
Digon3
Jarekt
Michael Büker
Aldaron
Michiel1972
Kimzoe200
Padraic
Sten
Moxfyre
Huwmanbeing
Twice25
AB
Imcall
Aviceda
DirkvdM
ClemRutter
Helentr
Liamgabby66
Diliff
Korax1214
Richard001
talk
Rodhullandemu
talk
Nichalp
QTH
= 18.56 N, 72.82 E, 12 m)
fr: user: Jean-Louis Hens
Specious
Giorgiomonteforti
Slaunger
CT Cooper
PhilipMay
KenWalker
Jim.henderson
Jeriby
Gapo
Igors Jefimovs
Senator2029
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be..anyone
Kelly
Almondega
Jason
Aabdullayev851
Siddikbabu
Goutam1962
talk
16:59, 16 April 2017 (UTC)
reply
Iketsi
Augusthorsesdroppings10
ActuallyNeverHappened02
Manoj Karingamadathil
Rkieferbaum
Ranjithsiji
talk
See also
Geocode Users
with
MediaWiki:Geocode Users.js
Commons:Geocoding/Panorama
Project to overlay Wikipedia-POIs over a panorama photo.
/Overlay
sub-project for creating KML map overlays on Commons.
MediaWiki:Exif-coordinate-format
controls the formatting for GPS information embedded in the EXIF metadata of images;
further info
Retrieved from "
Category
Wikimedia projects and maps
Hidden categories:
Commons geocoding
Pages with coordinates
Commons
Geocoding
Add topic