The world’s technologies have advanced dramatically over the last few decades with innovations likes the internet and satellite navigation having changed the way we live our lives.
Atomic clocks pay a key role in these technologies; their time signals are what are used by GPS receivers to plot location and many applications and transactions across the internet if it wasn’t for highly precise synchronisation.
In fact a global timescale has been developed that is based on the time told by atomic clocks. UTC (Coordinated Universal Time) ensures that computer networks across the globe can be synchronised to the exact same time.
Synchronising computers and networks to atomic clocks is relatively straight forward thanks in part to NTP (Network Time Protocol), a version of which is included in most operating systems and is also thanks to the number of public NTP servers that exist on the internet.
To synchronise a Windows PC to an atomic clock is done by simply double clocking the clock on the task bar and then configuring the Internet Time tab to a relevant NTP server. A list of public NTP servers can be found at the NTP pool website.
When configuring networks to UTC however, a public NTP server is not suitable as there are security issues about polling a time source outside the firewall. Public servers are also known as stratum 2 servers which means they receive the time from another device that gets it from an atomic clock. This indirect method means that there is often a compromise in accuracy, furthermore if the internet connection goes down or the time server site then the network will soon drift away from UTC.
A far more secure and stable method is to invest in a dedicated NTP time server. These devices receive a time signal directly from an atomic clock, either produced by a national physics lab like NIST or NPL via long wave radio or from GPS satellites.
A single dedicated NTP server will provide a stable, reliable and highly precise source of UTC and allow networks of hundreds and even thousands of devices to be synchronised to NTP.