Auto-geotagging

Auto-geotagging or automatic geotagging was first coined by MapWith.Us and refers to automating the process (U.S. patent pending) of acquiring media, associating location with the media, transferring the media to an online map and publishing the media in real time. Auto-geotagging with a media acquisition device (e.g. photographic or video camera) requires communication with location acquisition (e.g. GPS, wi-fi triangulation) and wireless data transfer devices. Modern cell phones (Blackberry Curve, iPhone 3G) integrate camera, aGPS, and wireless data transfer into one device, as do certain cameras, thus directly producing a geocoded photograph. Auto geotagging is sometimes referred to as "mobile geotagging", but this does not imply automation.

Location Acquisition

Geotagging is gaining popularity with photographers, however, most cameras do not possess the capability of determining location. Often photographers rely on external GPS receivers to determine location. Acquiring location from a stand alone GPS unit requires a lock from at least three satellites (for position) and usually requires up to 60 seconds, however, acquisition time is decreasing rapidly with hardware improvements. A new twist on conventional GPS receivers uses cell tower location and one global positioning satellite to obtain a faster lock on location. This technology known as assisted GPS (aGPS) is becoming more popular in cellular phones since it leverages cell tower locations. An alternative to GPS is WiFi triangulation which uses the MAC addresses of nearby wireless access points to determine position. Auto-geotagging relies on media acquisition devices that contain GPS, aGPS, or WiFi.

Real Time Media Transfer

Wireless data transfer is essential for auto-geotagging because it allows for real time mapping of media. Transferring images from cell phones to social networking sites is gaining popularity (see Facebook). Facebook and other sites promoting real-time media transfer have not attempted to associate location with the media since this requires mapping technology. Applications for real time mapping include travel, real estate, geo-social networking, people tracking, security, and geo-fencing.

Online Mapping

Geotagging becomes useful and relevant if you can present the geotagged media via a map. Advanced online mapping tools (e.g. MapWith.Us) allow auto-geotaggers to present data in a public, private, or protected venue. Associating a location with a media object on a map is currently driving the auto-geotagging market.However, presenting the data using online maps is a challenging problem, especially when combined with collaborative mapping (see collaborative mapping).

Privacy Concerns

Since auto-geotagging provides real-time location of the person operating the auto-geotagging device, it is possible to track that person. Where this is a problem, the geotagger can (by default) restrict online access to maps that are auto-geotagged, and decide at discretion to change access privileges.