Salesmen lost in Peoria, hikers disoriented in Utah, and fishermen trying to return to where the Big One got away are turning more and more to Pentagon satellites for directions.
The federal government's $12 billion Global Positioning System (GPS), once the preserve of military commanders, is increasingly accessible to the public and has begun reshaping the way people play, travel and work.
Officials at the Department of Defense and the Department of Transportation agreed last month to make the military's more accurate but long-restricted "L2" GPS signals accessible for civilian use. It was the latest government concession to the burgeoning commercial demand for better satellite navigation.
"Knowing where you are, where you are going and how to get there are becoming more and more important and useful," said George S. Fry, president of Aviso Micro Technology Co.
In a recent market research study for Forward Concepts of Tempe, Ariz., he estimated the worldwide market for civilian GPS technologies at about $2.5 billion in 1996, and $9.6 billion by 2000.
Completed just three years ago, the GPS system uses 24 satellites that orbit the Earth every 12 hours. They continuously transmit coded signals and time data that receivers use to compute latitude and longitude.
Already familiar to aircraft pilots and ship captains, GPS devices are turning up in rental cars and outdoors stores. Falling prices for the basic devices have encouraged more than 100 manufacturers to begin inventing and building new consumer applications.
At the Wild Wing Plantation -- a 72-hole golf resort at Myrtle Beach, S.C. -- head golf pro Tim Tilma needed something to distinguish his courses from nearly 100 others in the area. He chose a cart-mounted GPS system that tells players how far they are from the pin, helping them choose the proper club.
The system, ProShot, also gives golfers other tips on how to play the hole as they move down the fairway. "It's like an automated caddy," Tilma said.
In his pro shop, a computer map shows the position of every cart on the course. When a foursome lags, the computer alerts Tilma, who sends the players a message suggesting they pick up the pace.
This is not what the Defense Department envisioned when it began building the GPS system in the mid-1970s. Military planners wanted a satellite-based navigation system that would provide U.S. forces with secure, all-weather positioning data anywhere on the planet.
