Nowadays GPS is most commonly known for vehicle navigation solutions. However, the GPS system can be used for many other useful purposes. For instance, many computer network time synchronisation solutions, such as NTP time servers, use the atomic clocks on board each GPS satellite for accurate timing. The GPS system can be used as an accurate reference clock for synchronising time-critical applications on computers and networks. This article describes how computer systems can utilise GPS time and discusses what equipment is required to provide a precision timing reference.

The GPS system is a United States military system intended for global navigation. The GPS system is a space-based system, consisting of a network of 24 orbiting satellites. Precise navigation and positioning is achieved by utilising precision timing signals and triangulation between multiple satellites. In order to provide very precise time, each satellite has an integrated highly accurate atomic clock onboard. Each satellite broadcasts timing information to within a few nanoseconds of the correct time to provide positioning to an accuracy of better than 10m. This precise timing information can be used by NTP time servers and other computer timing equipment as a highly accurate time reference. The great thing about GPS is that it works anywhere in the world and is entirely free to air service.

Each GPS satellite transmits a low-power radio signal dow

By Haadi