(Redirected from Geotagging)'Geotagging', sometimes referred to as '
Geocoding', is the process of adding geographical identification
metadata to various media such as websites,
RSS feeds, or images. This data usually consists of
latitude and
longitude coordinates, though it can also include
altitude and place names.
Geocoding also refers to the process of taking non-coordinate based geographical identifiers, such as a postal address, and assigning to them
geographic coordinates.
Geotagging can help users find a wide variety of location-specific information. For instance, one can find images taken near a given location by entering a latitude and longitude into a Geotagging-enabled image search engine. Geotagging-enabled information services can also potentially be used to find news, websites, or other resources.
Geotagging in tag based systems
There exist a variety of techniques for adding geographical identification metadata to an information resource. One convention established by the website called
GeoBloggers, encourages users to add tags to their
Flickr images and
del.icio.us bookmarks, enabling them to be found via a location search. Both Flickr and del.icio.us allow users to add metadata to an information resource via a set of tags, see
folksonomy.
The convention established by GeoBloggers uses three tags to geotag an information resource:
★ geotagged
★ geo:lat=''latitude'' e.g. geo:lat=51.4989
★ geo:lon=''longitude'' e.g. geo:lon=-0.1786
where
latitude and
longitude are the geographic coordinates of a particular location. These are expressed in decimal degrees in the
WGS84 coordinate system, which has become something of a default coordinate system with the advent of
GPS.
Using three tags works within the constraint of having tags that can only be single 'words'. Identifying geotagged information resources on sites like Flickr and del.icio.us is done by searching for the 'geotagged' tag, since the tags beginning 'geo:lat=' and 'geo:lon=' are necessarily very variable.
A further convention proposed by
FlickrFly adds tags to specify the suggested viewing angle and range when the geotagged location is viewed in
Google Earth:
★ ge:head=xxxx e.g. ge:head=127.00, where xxxx is the view heading in decimal degrees (0-360) where zero is looking North.
★ ge:tilt=yyyy e.g. ge:tilt=60.00, where yyyy is the view tilt angle in decimal degrees, where 0 is looking straight down and 90 is looking horizontally from ground level.
★ ge:range=zzzz e.g. ge:range=560.00, where zzzz is the range of the viewpoint in
metres from the marker location.
Web sites
Geotagging
HTML web pages is done with
meta tags. The
GeoURL standard requires the ICBM tag:
The similar Geo Tag format allows the addition of placename and region tags:
Microformat
The
Geo microformat allows co-ordinates within web pages to be marked up in such a way that they can be "discovered" by software tools. Example:
50.167958;
-97.133185
which might display as:
50.167958; -97.133185
(and gives a live Geo
microformat on this page).
A proposal is in hand
[1] to extend Geo to cover other bodies, such as
Mars and
The Moon.
An example is the
Flickr photo-sharing web site, which provides geographic data for any
geocoded photo in all of the above-mentioned formats.
GeoTagging in Wikipedia
By adding the template, articles can be geotagged. Another template adds geo microformats automatically.
Geoblogging
Geoblogging is specifically giving the area a log of events. Sites like
★
www.grapheety.com specialize in this area. Geotag specifically passes information in the format of digital latitude and longitude co-ordinates.
Geoblogging is attaching user experience in the form of 'text and pictures' to a specific geographic location denoted through 'geotag'. Reading a list of blogs and pictures denoted through the application of geotag technology is more interesting and allows users, through interactive maps, to select areas of specific interest to them.
Geoblogging is of particular interest to those in the 'travel field', be it travellers or holiday makers or professionals. The progression of GPS technology has, along with the development of applications in Flickr, allowed users to give a geospatial fix to where their travel photos were taken.
See also
★
Geocaching
★
Geographic information system (GIS)
★
Global Positioning System (GPS)
★
Tagging
★
Geocoded photo (Geotagging methods)
★
Geolocation
External links
★
GeoURL
★
Geotags
★
MyGeoPosition.com (Geocoding of addresses, creation of geotags and geo-metatags)
★
GeoRSS
★
W3C Semantic Web Interest Group
★
"Location, Location, Location" Wall Street Journal
★
I-Draft for HTML Geotags
★
I-Draft for HTTP Geoheader
★
IETF Geographic Location/Privacy (geopriv) Group
Geoblogger sites
★
www.maptales.com
★
Socialight
★
www.geobloggers.com
★
www.grapheety.com
★
www.michaeltyler.co.uk
★
Woophy