Outdoors, assisted Global Positioning System (AGPS) is the most effective positioning solution currently available. With accuracy down to one meter in optimal conditions, GPS can provide real-time tracking of visitors’ movements and respond with location-based content delivery. GPS does not, however, currently work indoors, and can be interrupted by tall buildings and heavy foliage as it is a line-of-sight technology (like IR) that requires a clear ‘view’ of the user’s GPS device by the satellites that then triangulate the user’s location.

At Ashton Court Manor in Bristol, England, GPS-enabled multimedia players ping users when they have entered an area that has interpretation, allowing the visitor to then play audio-visual commentaries for selected areas of the 850-acre site. A map also displays the user’s current location as a blinking red dot that moves across the map as the visitor moves through the grounds. GPS has also been trialled in a tour of Hadrian’s Wall in Carlisle, Scotland and in a number of handheld city tours, including Appleby, Lancaster University’s GUIDE project, and the m-ToGuide project tours of London, Siena and Madrid.

GPS is becoming more common in taxis and cars, with a range of consumer versions now available for everything from driving to hiking and sailing. The ubiquity of GPS in every day navigation has raised the bar for location-based solutions in cultural settings; often visitors ask why a museum can’t simply install GPS to help with wayfinding, and this is likely to remain the standard to which positioning systems for interiors aspire for some time to come.

In short, the posibilities of GPS can be explained in three words: Determing a position. Guided tours and urban games can use this in the following ways:

• Find coördinates or locations

  Give the user the gps coördinates of an item or place. An example of this is Geocaching.

• Follow a moving person or object

  By giving someone or something a gps receiver, systems can track his/her/its movements. Only found a dutch example so far: Hunted. In short it's a game where a city turns into a hunting ground for one day. One team constantly hunts, the other team is on the run.

• Being followed

  Let other people follow you around. Several websites on the internet offer this service for friends. In the game mentioned above, the hunteds (as the 'preys' are called) can be followed by their gps signal (this is probably with some delay). Another dutch example (at the top right, there's a button to translate text into english)

• Pinpoint locations

  'Always something somewhere else' from the mscapes website lets you determine your own locations which you have to find back afterwards.

• Set routes

  Let other people follow you around. Several websites on the internet offer this service for friends. This way, software actually draws your exact path. A fun way of using this technique.

• Visit random locations

  By gving the user freedom in where he wants to go to, you can trigger events like movies or sounds at specific locations.

   

Although the several ways of using gps can almost be called obvious, it can help to have them all in a row to determine which one suites you best. If you are new to gps and you want to find out what can be done in a tour, mscapes can be recommended. It's free and it's fairly easy to use. (Has some problems with windows Vista as it seems)