For our radio controlled clocks, we have been advised that the radio signal has been moved from Rugby to Cumbria. Details as follows:
Why is the time signal moving from Rugby to Anthorn?
The existing contract between NPL and BT for the broadcast of the signal from Rugby expires at the end of March 2007. Following studies into whether the signal was still required and what alternatives were available, a contract for a replacement service was put up to tender and VT Communications emerged as the preferred option.
How will the general public be affected by this change?
They are unlikely to be affected. There will be small changes in signal strength as a result of the relocation, but they should not have a noticeable effect on reception of the signal.
How will the switch from Rugby to Anthorn happen?
Once the system is set up and tested, a series of active tests will be undertaken during which the Rugby transmission will be switched off and the Anthorn transmission switched on for a period of time to ensure that the service is performing as expected. These tests are expected to start at the end of 2006. After 31 March 2007 the Rugby signal will not be switched back on, and the Anthorn signal will operate continuously.
Will there be any disruptions to the service during the changeover?
There should not be any disruption to people using the signal as a timing reference. Users employing the signal as a frequency reference will see a jump in the carrier phase whenever transmission switches between Rugby and Anthorn, and may have to avoid using the signal during these events.
What services/applications use the Time from NPL?
The UK timescale operated by NPL is a measurement standard that permeates all aspects of our lives, both supporting high precision applications (e.g. geodesy, telecommunications) and providing the correct time of day at relatively low accuracy to co-ordinate our everyday activities. Time standards affect everyone in some shape or form, but there are less than 60 measurement institutes around the globe that together define Coordinated Universal Time (UTC) as the common timescale for the world and maintain their national timescales to provide practical access to UTC. NPL makes UK time available through its own services together called NPL Time (including the radio broadcast, internet time servers, and telephone services), and by monitoring third party broadcasts (e.g. GPS signals) and publishing bulletins giving the differences between those timescales and UK time. For the most demanding users, NPL will monitor any precise clock directly against its own timescale using GPS satellite signals.
Some examples of user applications are: synchronising telecommunications and broadcast networks; synchronisation and fault-location in electricity grids; time scales used in satellite navigation systems; lightning detection systems; synchronising time servers in computer networks; time-stamping for data loggers and financial transactions; synchronising clocks and monitoring systems for transport applications - rail, sea, road and air; etc.
Why is accurate time important to the man on the street?
At one extreme the synchronisation of clocks to a few nanoseconds allows the Global Navigational Satellite Systems to be accurate to a few metres, and in-car navigation systems to work. But at the more mundane level a recent court case was won because the police could demonstrate (with NPL's help) that telephone records from different mobile operators were both linked to the UK timescale and could demonstrate a sequence of events to the second.
Is the signal affected by weather at all e.g. if there was a rainstorm or a hurricane, would this alter the time signal?
No, unless the hurricane knocked down the mast! Bad weather cannot alter the transmitted time code. However, brief interruptions occur occasionally as a result of ground currents caused by lightning strikes near by damaging circuits in the transmitter. The signal also propagates better when the ground is wet than when it is dry.