GPS (Global Positioning System) is a worldwide satellite-based navigation system formed from a constellation of 24 satellites. It has become a universal positioning and navigation system for military, research, commercial, and personal applications. GPS is used to pinpoint specific locations, provide real-time navigational directions, track an object, and create global maps.

GPS was developed by the US Department of Defense for military use; however, it is available for free for personal and commercial use. The first GPS satellite was launched in 1978 and in 1994 all 24 satellites were in place.

In simple terms, GPS satellites broadcast information to earth. A GPS receiver takes the information from the satellites in view and translates it into three-dimensional position, time, and velocity. Commercial GPS receivers are typically accurate within 3-5 meters (within 3 meters if a real-time correction method is used). The system supports an unlimited number of users across the world. GPS is usable anywhere in the world- on land, sea, and air- except where it's not possible to receive the satellite signal, like underwater or in most buildings.

GPS receivers can be integrated with a laptop computer, attached to a vehicle, or integrated into a mobile phone or PDA. A GPS receiver can be used with a transponder or transmitter; the transmitter can gather the information from the receiver and send it to a station, like a dispatcher or enterprise application. The European Space Agency and European Union have been designing and developing their own satellite navigation system, Global Navigation Satellite System (GNSS), or Galileo. Galileo will be the first satellite system built for civilian purposes. It is planned to be operational with 30 satellites by 2008. Galileo will be interoperable with the US GPS system, allowing the system to be interconnected seamlessly and improving the accuracy and reliability of the system.

GPS Applications

GPS offers a host of applications for commercial and recreational use. When combined with enterprise or ASP software, GPS technology can improve customer service, operational efficiency, and security for companies in diverse industries.

Automatic Vehicle Location (AVL): With GPS, supervisors and dispatchers have real-time visibility into route operations. In the taxi industry, dispatchers can automatically assign the closest vehicle to a customer. With complementary applications, managers can receive automatic alerts if vehicles deviate from planned routes. AVL also facilitates a speedy recovery of stolen vehicles.

Asset Management: With GPS, companies can track rental vehicles, expensive cargo, trucks, or trailers. For large and geographically dispersed assets/fleets, GPS enables automatic inventory reporting of the company's mobile assets.

Navigational Assistance: GPS is also used for navigation for general aviation, commercial aircraft, commercial fisherman, and recreational boaters. GPS systems are becoming quite popular in automobiles, providing driving directions in real-time. Systems also provide emergency roadside assistance by transmitting exact location to a dispatch center. GPS-enabled phones give you turn-by-turn directions via your handset.

Location-Based Services: The usage and availability of location-based services are on the rise. These services incorporate intelligent directory assistance, guide book help, and driving directions. Whether on foot or driving, users can find the closest hotel gas station, restaurant, etc.