Civilian Benefits of Discontinuing Selective Availability

May 1, 2000

Discontinuing the use of Selective Availability (SA) will improve the predicted accuracy of GPS for civilian users from within 100 meters (about 300 feet) to within 20 meters (about 60 feet). In many cases, real-world users will find the accuracy to be even better. This performance boost will enable GPS to be applied in its most basic form to a variety of civilian activities -- land, sea, air, and space -- where it could not previously.

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. It should also fuel the continued growth of the global GPS market, currently estimated at over $8 billion, as well as the market for geographic information services in general.

Listed below are several examples of the civilian benefits derived from discontinued use of SA.

Transportation

Emergency Response

Land

Recreation

Space

Timing

Need for Higher Performance

Even with SA turned off, GPS alone will not meet all users needs. For users with higher accuracy, availability, and integrity requirements -- such as commercial airlines, ships navigating within harbors, railroads performing precise train control, precision farmers and miners, and surveyors -- GPS will still need to be augmented locally with high-fidelity error correction systems based on differential GPS (DGPS) technology. The U.S. is also adding two new civilian signals to future GPS satellites to further improve accuracy and reliability on a global basis. But for the many other users listed above, the elimination of SA will enable the most inexpensive, standalone GPS receivers to meet their needs.

Additional information about GPS and the Interagency GPS Executive Board is available online at http://www.igeb.gov