The Global Positioning System (GPS) is a great technological success story. It was developed by the Department of Defense (DoD) primarily for the U.S. military to provide precise estimates of position, velocity, and time. First Civil use was a secondary objective. On the basis of national security considerations, the civil users of GPS have been limited to a purposefully degraded subset of the signals. Nevertheless, the civil applications of GPS have grown at an astonishing rate. Applications unforeseen by the designers of the system are thriving, and many more are on the way. GPS has found applications in land transportation, civil aviation, maritime commerce, surveying and mapping, construction, mining, agriculture, earth sciences, electric power systems, telecommunications, and outdoor recreational activities. This Special Issue of these PROCEEDINGS offers a survey of the GPS technology and some of its civil applications. we begin this essay with a short introduction to GPS: the system, signals, and performance. The objective is to provide the necessary background and to introduce the basic concepts and vocabulary needed for the papers, which follow.
GPS is widely seen as the most important gift of the DoD to the civil world, perhaps with the exception of the Internet. Civil applications unforeseen by the developers of the system are thriving and many more are on the away. Commerce in GPS equipment and services continues to grow rapidly. This success has also created expectations, indeed demands, which the system was not designed to meet. It is expected that the planned GPS modernization, when complete, would make determining position as easy as determining precise time is today. This knowledge of position would come to occupy the same important place in our daily lives as time does today.
