Commons geocoding – wikimedia commons electricity distribution vs transmission

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.

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. Adding Geotags before uploading [ edit ]

Some software, such as Microsoft Pro Photo Tools or Picasa *, 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.

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 [ edit ] Zoom levels OSM

• 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.

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

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

• 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.

• 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.

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