9. GPS for timing things

Although GPS is well-known for navigation, tracking, and mapping, it's also used to transmit precise time, time intervals, and frequency.

GPS satellites carry highly accurate atomic clocks.

Each GPS satellite has an atomic clock onboard

 

And in order for the system to work a GPS receiver here on the ground 'locks' itself to that atomic clock. That means that every GPS receiver is, in essence, an atomic accuracy clock.

 

Why do people want to know the precise time?

When things need to happen at exactly the same time around the world then GPS comes to its own.

For example astronomers across the world may want to make their telescopes track the same object at exactly the same time to allow them to make more accurate observations, for example tracking an asteroid

 

 

Computer networks

These rely on precise clocks to make sure everything happens in the right order, worldwide computer networks need to have a "world clock" to keep themselves synchronised. GPS provides this clock.

 

Television stations

With 24 hour world wide news, it is quite normal these days to see events occuring around the world and for people in different countries to commentate on them as they happen. This can only be done by using precise timing using GPS as a clock.