GPS in fact broadcasts two different kinds of signals-a Coarse/Acquisition code intended for civilian use and an encrypted Precision code for the US military. The devices can do this, that is, if the US allows such accuracy. Location can be pinpointed to within 33 feet. The signals are so accurate that time can be determined within a millionth of a second and speed within a fraction of a mile per hour. The receivers calculate how long it has taken them to receive the radio pulses from different GPS satellites-and use the barely perceptible differences in time to figure out a position on the face of the Earth, as well as velocity at which one is traveling. “It was seen as a better navigational tool.” “When the Global Positioning System was being developed and first deployed, no one was talking about using it for bombing,” Myers told the Senate Armed Services Committee. Myers, Chairman of the Joint Chiefs of Staff, last year. It has also turned out to be one of the most important US government investments in space, creating a $30 billion a year civilian market in GPS–related devices.įor the military, GPS has been revolutionary, taking the “search” out of search and rescue, guiding troops through trackless deserts, and-perhaps most importantly-providing US airpower with the basis for unmatched all-weather Precision Guided Munitions.įor PGMs, GPS capability is as much of an advance over laser guidance as laser guidance was over “dumb” bombs, noted Air Force Gen. Conceived as a navigational aid for ships, it is now a sort of sextant to the world, as important in its own way as the discovery, in the 18th century, of means of measuring longitude at sea.
Twenty-five years later, they have figured it out, and GPS has become one of the most successful and versatile high-technology projects of all time.
They were aware of its capability-the provision of pinpoint location information-but had little idea how that could be exploited to increase the effectiveness of United States forces. At the time, even many Pentagon officials were not exactly sure what this unheralded new system would do. The event received little notice in the press. 22, 1978, the first Block I Navstar Global Positioning System satellite was launched from Vandenberg AFB, Calif.
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