3.14 Location-Based Services
Services (LBS) are applications that take your geographic
location (city, state, location of your mobile device, etc.) into consideration.
While the term generally refers to services accessed on mobile devices
using the Global Positioning System (GPS), it can also be used to describe
web applications that take your location into account. Search
engines including Yahoo! Local and Google Maps use localization
to provide you with geographically relevant content. Local search is
particularly useful when you want to find a nearby business (e.g., plumbers,
taxis, etc.). Location-based services are becoming increasingly popular
in Web 2.0 applications. Conferences related to LBS include O’Reilly’sWhere 2.0 and the Location Intelligence Conference.
Global Positioning System (GPS)
The Global Positioning System (GPS),
developed by the United States Department of Defense,
uses numerous satellites that send signals to a GPS receiver to determine
its exact location. (A Russian system called GLONASS also exists, and
a new system named Galileo is under development in Europe.) In the 1980s,
the US Department of Defense opened GPS for civilian use to encourage
satellite technology development.1 Numerous location-based services are now available using GPS technology,
such as GPS mapping devices used in cars or on mobile devices. GPS is
also being used for safety. The US Federal Communications Commission
(FCC) now requires wireless carriers to provide the locations of wireless
customers calling 911 so emergency services can find them faster. To
meet this requirement, wireless carriers have developed GPS-enabled
cell phones.2 These phones also provide premium services, such as driving directions
and local information. The Disney Family Locator service
uses GPS-enabled phones to help parents keep track of their children
(as long as the child is carrying the special cell phone).3
Maps is one of the most popular mapping applications available
online. You can use Google
Maps to locate businesses in your area, get driving directions
and live traffic information, create custom maps with images and more.
You can even get the information by using your mobile device. Google’slocal search allows you to locate
a business in a geographic area and get its address, phone number, driving
directions and even user reviews. Google
Earth provides satellite images of virtually any location
on the planet. In some areas, you can even get a panoramic view of a
neighborhood at street level. You can use the Google Maps API to add
mapping capabilities to your websites and web applications.
MapQuest, owned by AOL, provides
similar mapping services. Use it to get directions and maps on your
desktop or mobile device. The MapQuest OpenAPI allows you to add location-based
services to your web applications. Additional mapping services include
Yahoo! Local Maps and MSN Live Search. Both services offer maps, driving
directions, traffic information and local search.
Companies such as NAVTEQ andTele Atlas provide digital map data for
in-vehicle and portable navigation devices, websites, location-based
services and more. Developers building commercial location-based services
can license the robust mapping products from these companies to build
richly functional web applications.
GeoRSS and Geotagging
GeoRSS, based on the RSS
standards, is a set of standards for representing geographical information
in a feed. Location and geographical information in a GeoRSS feed can
be used in GPS devices, mapping applications and other location-based
services. For example, a blog post about a vacation could map the locations
Geotagging can be used to
add location information (longitude, latitude, etc.) to websites, images,
RSS feeds, videos and more. Websites can often determine a user’s
location by their IP address. Geotagging a website provides the user
with location information about the site.5 Geographic information can be used to add value to search results.
Geotagging could also be mashed up with existing visualization systems,
such as Google
Earth or MSN Virtual Earth, which provide
advanced satellite images for anywhere on the planet.