Global Positioning System-the newest utility

The Global Positioning System (GPS) has become the high tech utility of the 20th century. It was developed by the US Department of Defense as a precise navigation reference for the military services. Although the signal available to civilian users had been purposely degraded in what is called selective availability (SA), it is one of a few technological success stories that had positive unintended consequences. Recent announcements indicate that this SA impediment has been removed. GPS currently has a huge civilian market in commercial and private aviation, ship navigation, mapping and surveying, telecommunications position determination, and recreational boating and hiking. By 2003 sales of GPS based products are expected to be $16 billion