National Physical Laboratory

Precision time for satellites

NPL will be providing the time for Europe's ambitious Galileo constellation of 30 global navigation satellites.

Once completed, Galileo will provide a guaranteed global positioning service under civilian control, with accuracy to within a meter on the ground.

Precision time for satellites

The signal from a navigation satellite travels at light speed - 300-million meters a second - so a tiny error in a time signal can throw navigation a long way off course. This means the satellites need precise and synchronised time.

NPL is part of a core consortium of nine European organisations developing the Galileo Time Service Provider (TSP). It is developing algorithms that will draw upon time data from atomic clocks across the world for transmission to the clocks at Galileo ground stations controlling and managing the orbiting satellites.

It was NPL that developed the first caesium atomic clock in 1955, paving the way for global time keeping based on atomic clocks. This world-leading expertise in time metrology will enable NPL and its partners to provide Galileo with time accurate to within 28 billionths of a second.

This will help Galileo to support a range of time-dependent applications such telephone networks, digital broadcasting and the Internet, as well as giving everyone access to a reliable source of time for everyday situations.

Find out more about NPL's research in Space & Communications and Time & Frequency

Last Updated: 8 Oct 2012
Created: 12 Nov 2010


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