Posted by Richard N Williams on October 6th, 2010
The atomic clock is unrivalled in its chronological accuracy. No other method of maintaining time comes close to the precision of an atomic clock. These ultra-precise devices can keep time for thousands of years without losing a second in drift – in comparison to electronic clocks, perhaps the next most accurate devices, which can drift up to a second a day.
Atomic clocks are not practical devices to have around though. They use advanced technologies such as super-coolant liquids, lasers and vacuums – they also require a team of skilled technicians to keep the clocks running.
Atomic clocks are deployed in some technologies. The Global Positioning System (GPS) relies on atomic clocks that operate onboard the unmanned orbiting satellites. These are crucial for working out accurate distances. Because of the speed of light that the signals travel, a one second inaccuracy in any GPS atomic clock would lead to positing information being out by thousands of kilometres – but the actual accuracy of GPS is within a few metres.
While these wholly accurate and precise instruments for measuring time are unparalleled and the expensive of running such devices is unobtainable to most people, synchronising your technology to an atomic clock, in actual fact, is relatively simple.
The atomic clocks onboard the GPS satellites are easily utilised to synchronise many technologies to. The signals that are used to provide positioning information can also be used as a source of atomic clock time.
The simplest way to receive these signals is to use a GPS NTP server (Network Time Protocol). These NTP servers use the atomic clock time signal from the GPS satellites as a reference time, the protocol NTP is then used to distribute this time around a network, checking each device with the GPS time and adjusting to ensure accuracy.
Entire computer networks can be synchronised to the GPS atomic clock time by using just one NTP GPS server, ensuring that all devices are within milliseconds of the same time.