Technology Positioned to Improve Safety

It's rare that someone can press a button and make something you already own worth more, but that's exactly what happened on May 1 of this year. The U.S. government opened to the public its Precise Positioning System, formerly available only for military use. This decision suddenly made all GPS receivers for boats, cars, and recreation ten times more accurate.

Performance Boost Serves Growing Market

The Global Positioning System (GPS) was designed to provide highly accurate positioning and timing data for both military and civilian users. Its primary purpose was to enhance the effectiveness of U.S. and allied military forces. The basic GPS consists of satellites, ground stations, data links, and associated command and control facilities which are operated and maintained by the U.S. Department of Defense.

GPS has always been the dominant standard satellite navigation system thanks to the U.S. policy of making both the signal and the receiver design specification available free of charge.

However, the Department of Defense deliberately reduced the precision of the civilian part of the GPS system for security reasons. Only authorized users with cryptographic equipment and keys, and specially equipped receivers were allowed access to the Precise Positioning System. For others, the signal was intentionally degraded by the use of Selective Availability (SA).

This discrepancy changed on May 1, when President Clinton announced his government would discontinue SA, allowing the public to benefit from the full potential of the technology. The increased performance of GPS, which is broadcast free of charge to the entire world, is expected to accelerate its acceptance and use by businesses, governments, and private individuals around the globe. This should lead to increases in productivity, efficiency, safety, scientific knowledge, and quality of life.

With more than 4 million users world wide, the market for GPS is set to double in the next three years. Applications include: air, road, rail, and marine navigation, precision agriculture and mining, oil exploration, environmental research and management, telecommunications, electronic data transfer, construction, recreation and emergency response.

Safety Benefits

Access to the non-degraded signal allows users to pinpoint the exact location of an emergency. This performance boost will significantly improve response times while reducing costs, and will enable applications which would not have otherwise been possible. Following are a few examples:

Search and Rescue: With SA turned off, GPS will become a more powerful and compelling tool in helping rescue teams search for individuals lost at sea, on mountains or ski slopes, in deserts, and in wilderness environments.

Roadside Assistance: Disabled cars equipped with GPS systems such as OnStar will be able to more accurately transmit their location, speeding response times for tow trucks and other services. With SA zeroed, the car's GPS signal will be able to identify which side of the road the car is on — an extremely important distinction if the local road, or interstate freeway, is divided by a concrete divider.

Enhanced 911: New cellular phones will soon be equipped with more accurate location determination technology to improve responses to emergency 911 calls. Removing SA will boost the accuracy of GPS to such a degree that it could become the method of choice for implementing the 911 requirement.

Fleet Management: Companies managing fleets of vehicles such as taxicabs, buses, commercial trucks, and rental cars will enjoy increases in efficiency as their ability to track and route individual vehicles improves. This will be especially important in crowded parking lots and railroad yards, where SA previously made it impossible to identify specific vehicles, tractor trailers, or boxcars using GPS alone.

For additional information about GPS and the Selective Availability decision visit the Interagency GPS Executive Board web site.

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