Geotags

= Geotags =

toc Geotags are tags used to add geographical metadata to digital files. The tags are composed of latitude and longitude coordinates although geotags can also include altitude, bearing, distance and other data. Geotags are most commonly used on photographs, although they can be added to files such as video, sound (to identify recording location), news articles, SMS messages and others where location could provide useful information.

One of the most common uses of geotags, attaching them to photographs, at its simplest allows photographers to sort images by location with ease. Photographs that are open to the public on sites such as Flickr, Picasa, Panoramio and others can be linked to by other applications such as Google Earth so that people can find and view pictures of an area. Panaramio is a site specifically for geotagged photos.

Uses of geotags
Combine a database of GPS mapped plants in a huge botanical garden with cultural information and photographs for a fabulous horticultural resource. http://plantexplorer.longwoodgardens.org/ecmweb/ECM_Home.html
 * Longwood Gardens Plant Explorer**

http://wiki.openstreetmap.org/wiki/Main_Page
 * OpenStreetMap**

http://wiki.openstreetmap.org/wiki/WikiProject_Haiti/Earthquake_map_resources
 * OpenStreetMap WikiProject Haiti/Earthquake map resources**

http://www.wikimapia.org
 * Wikimapia**

http://www.lampos.net/files/Poster_Flu_Detector_Tracking_Epidemics_on_Twitter_v.2.0.pdf
 * Flu Detector - Tracking Epidemics on Twitter**

http://www.foodspotting.com/
 * Foodspotting**

**Location based social networking**
Foursquare, Facebook, and Twitter are the most well-known players in the location-based, geotagging social networking

How to Add Geotags
media type="youtube" key="yH01BfcaUao" height="208" width="350" align="right"

Geotags can be added to digital photographs or videos in two main ways. GPS data can be added to the photograph as it is digitally created, either with a camera with built in GPS unit of with a GPS unit that can be attached to the camera. Cell phones create location data either from a GPS chip or by triangulation from nearby cell towers, and so camera-phone photographs are automatically tagged. Currently a still fairly small percentage of digital cameras have built in GPS, so often an attached GPS unit will be used.

The other way that location metadata can be added is after the fact using software or online applications with maps. By narrowing in on the location where photographs were taken, and clicking on the map, the information can be added to either the original image or an online copy.

Picasa is owned by google and so it’s geotagging is tied into Google Earth. Flickr, owned by Yahoo, uses media type="youtube" key="-AD_HriH2lE" height="208" width="350" align="right" Yahoo!Maps for it’s geotagging app.

Although Flickr contains an easy method to geotag photos by map, it does not write the metadata to the original image files. It is difficult to get information applied only to the Flickr copy out of Flickr, so it is best to geotag images before uploading them. This may apply to other photosharing websites that add geotags with maps. In order for information to be easily retained with the image it should be written to either EXIF or IPTC data files, so that it can easily be downloaded.geotagging app.

[|Several different formats and standards] are used in writing geotags. One convention commonly used by geobloggers and on Flickr and Delicious is writing the data in machine tags. Examples of geotags written in machine tag syntax: geo:lat=* [replace the star with the latitude] geo:lon=* [replace the star with the longitude] geo:alt=* [replace the star with the altitude]



Geotagging Hardware
[|Video on using GPS hardware and software] to automatically or semi-automatically attach geotags to photographs.

Geotagging software
GeoSetter is a freeware tool for Windows (XP or higher) for showing and changing geo data and other metadata (IPTC/XMP/Exif) of image files http://www.geosetter.de/en/

Geotag is an open source program that allows you match date/time information from photos with location information from a GPS unit or from a map http://geotag.sourceforge.net/

Geotag Use in Libraries
media type="custom" key="11614492" align="right"Location data is valuable on all kinds of resources, but particularly photographs and items specific to a particular area. Being able to asso ciate and object with a place allows association of information with communities, and associated information on political, social and environmental conditions in the area.

Privacy issues
The greatest concern posed by geotagging and related location information is the effect on privacy. Mobile devices such as the iPhone and increasing numbers of other phones and tablets equipped are routinely with GPS locators, partly to fulfill the requirements of [|Phase 2 of the E911 Act] in order to make it easier for emergency responders to quickly locate callers.

When combined with automatic check-ins through social location sharing sites such as FourSquare, Gowalla, Twitter and Facebook, they can allow anyone to see your location at anytime. This has led to instances of burglary where the victim was known not be at home. It can also facilitate cyber-stalking. Instant uploading of automatically geotagged photos from phone cameras results in the same problem. It can also reveal that a person was in a different location than expected by an employer or spouse, leading to potential personal repercussions.

Because photographs often contain embedded geolocation information in attached EXIF or IPTC files, they can be used to locate houses or items when posted on the internet. There for it is wise to strip out this information before posting images of valuables for sale to sites such as Craigslist, eBay or other advertising sites. Two websites that inform people of the hazards of public location sharing and how to avoid them are [|Please Rob Me] and [|I Can Stalk U]