02 May 2010
Posted in G
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Geotagging - Geotagging is the process of adding geographical identification metadata to various media such as photographs, video, websites, or RSS feeds and is a form of geospatial metadata. These data usually consist of latitude and longitude coordinates, though they can also include altitude, bearing, distance, accuracy data, and place names. It is commonly used for photographs, giving geotagged photographs.
Geotagging (also written as GeoTagging) is the process of adding geographical identification metadata to various media such as a Geotagged photograph or video, websites, SMS messages, or RSS feeds and is a form of geospatial metadata. These data usually consist of latitude and longitude coordinates, though they can also include altitude, bearing, distance, accuracy data, and place names. It is commonly used for photographs, giving geotagged photographs.
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 latitude and longitude coordinates into a suitable image search engine. Geotagging-enabled information services can also potentially be used to find location-based news, websites, or other resources. Geotagging can tell users the location of the content of a given picture or other media or the point of view, and conversely on some media platforms show media relevant to a given location.
The related term geocoding refers to the process of taking non-coordinate based geographical identifiers, such as a street address, and finding associated geographic coordinates (or vice versa for reverse geocoding). Such techniques can be used together with geotagging to provide alternative search techniques.
The base for geotagging is positions. The position will, in almost every case, be derived from the global positioning system, and based on a latitude/longitude-coordinate system that presents each location on the earth from 180° west through 180° east along the Equator and 90° north through 90° south along the prime meridian.
There are two main options for geotagging photos; capturing GPS information at the time the photo is taken or “attaching” the photograph to a map after the picture is taken.
In order to capture GPS data at the time the photograph is captured, the user must have a camera with built in GPS or a standalone GPS along with a digital camera. Because of the requirement for wireless service providers in United States to supply more precise location information for 911 calls by September 11, 2012, more and more cell phones have built-in GPS chips. Some cell phones like the iPhone and Motorola Backflip already utilize a GPS chip along with built-in cameras to allow users to automatically geotag photos. Others may have the GPS chip and camera but do not have internal software needed to embed the GPS information within the picture. A few digital cameras also have built-on or built-in GPS that allow for automatic geotagging such as Nikon, Sony and Ricoh. Devices use GPS, A-GPS or both. A-GPS can be faster getting an initial fix if you are within range of a cell phone tower, and may work better inside buildings. Traditional GPS does not need cell phone towers and uses standard GPS signals outside of urban areas. Traditional GPS tends to use more battery power. Almost any digital camera can be coupled with a stand alone GPS and post processed with photo mapping software such as GPS-Photo Link, Alta4, or EveryTrail to write the location information to the image's exif header.
Geographic coordinates can also be added to a photograph after the photograph is taken by “attaching” the photograph to a map using programs such as Flickr and Panoramio. These programs can then write the latitude and longitude into the photos exif header after you have selected the location on a map.