Posted by Stuart on April 28th, 2009
The GPS network (Global Positioning System), is commonly known as a satellite navigation system. It however, actually relays a ultra-precise time signal from an onboard atomic clock.
It is this information that is received by satellite navigation devices that can then triangulate the position of the receiver by working out how long the signal has taken to arrive from various satellites.
These time signals, like all radio transmissions travel at the speed of light (which is close to 300,000km a second). It is therefore highly important that these devices are not just accurate to a second but to a millionth of a second otherwise the navigation system would be useless.
It is this timing information that can be utilized by a GPS time server as a base for network time. Although this timing information is not in a UTC format (Coordinated Universal Time), the World’s global timescale, it easily converted because of its origin from an atomic clock.
A GPS time server can receive the signal from a GPS aerial although this does need to have a good view of the sky as the satellites relay their transmissions via line-of-sight.
Using a dedicated GPS time server a computer network can be synchronised to within a few milliseconds of NTP (milli=1000th of a second) and provide security and authentication.
Following the increase use of GPS technology over the last few years, GPS time servers are now relatively inexpensive and are simple and straight forward systems to install.