Do GPS Devices Require Subscriptions?by Richard Asmus
You can use a Global Positioning System receiver anywhere you go on Earth to exactly pinpoint your location. You can mount a GPS in your car, on the handlebars of a bicycle, carry it in your pocket or wear it on your wrist. As long as it can pick up signals from at least three of the GPS satellites, it will calculate your location. There is no subscription service required to use a GPS device, although some additional and enhanced services do cost money.
The United States Department of Defense operates and maintains a system of satellites that orbit the earth in a pattern that sends signals to all locations at all times. Twenty four satellites actively send signals and up to three more remain in orbit as spares to take over if any fail. Originally designed for defense purposes, the DOD now allows anyone to use the signals free of charge to calculate longitude, latitude and altitude. Other companies, however, sell subscription services that work along with the signals to provide enhanced information.
Map Sales and Update Subscriptions
A more elaborate GPS superimposes your location over various types of maps. Some are graphic maps, some are satellite photos and others include more detailed information for specific areas, such as golf courses and ski resorts. Most GPS mapping devices offer two options: the purchase of individual maps without updates or subscription services that include one or more types of maps and automatic updates as information changes and new areas are covered. Monthly prices vary widely according to the number and type of map services ordered.
Subscription Traffic Services
Some GPS services offer traffic subscriptions that send real-time local traffic information to your system. More elaborate programs give you alternate routing information to guide you away from construction areas, traffic jams and accidents. Subscription prices vary. Some companies offer advertising information for various types of businesses to guide potential customers through traffic to their locations.
Subscription Information Services
Some companies offer free email subscriptions to provide ongoing GPS system development information. They also offer services that include more elaborate online information and monthly print magazines sent by regular mail. They can cover information for a single country, a geographical area such as Europe or North America or the entire world.
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