Bringing precise time to the world
"When will it all happen?"
Although GPS is well-known for navigation, tracking, and mapping, it's also used to
disseminate precise time, time intervals, and frequency. Time is a powerful commodity, and
exact time is more powerful still. Knowing that a group of timed events is perfectly
synchronized is often very important. GPS makes the job of "synchronizing our
watches" easy and reliable.
There are three fundamental ways we use time. As a universal marker, time tells us when
things happened or when they will. As a way to synchronize people, events, even other
types of signals, time helps keep the world on schedule. And as a way to tell how long
things last, time provides and accurate, unambiguous sense of duration.
GPS satellites carry highly accurate atomic clocks. And in order for the system to
work, our GPS receivers here on the ground synchronize themselves to these clocks. That
means that every GPS receiver is, in essence, an atomic accuracy clock.
Astronomers, power companies, computer networks, communications systems, banks, and
radio and television stations can benefit from this precise timing. One investment banking firm uses GPS to guarantee their
transactions are recorded simultaneously at all offices around the world. And a major Pacific Northwest utility company makes sure their power is
distributed at just the right time along their 14,797 miles of transmission lines.