Radio Time Signal Rugby
NTP Server Reference Clocks: What's Best Radio or GPS?
A NTP server is a network device that provides network servers and other infrastructure network with a precision reference clock. A NTP Server obtains precise time of an external time source, such as time and frequency radio broadcasts or GPS. This article describes the external time references that are available to synchronize NTP servers and discusses the merits of each.
There are a number of radio and transmission time at frequencies that are available in various places. The WWVB signal is a U.S. based reference, DCF-77 in Germany and MSF in the United Kingdom. These time and frequency radio broadcasts to provide a stable and accurate source of time. In addition, an internal antenna located radio can be generally be used to receive these signals – reducing installation costs. However, radio signals can be affected by local topography – such as hills and valleys. There is no guarantee of receiving radio signal still within the range of the signal transmission.
The MSF radio signal broadcast in the UK by the National Physics Laboratory recently moved Rugby in the East Midlands to Anthorn in Cumbria. Since the move has been widely recognized that the reception in the south of England has suffered – despite which is within the range of physical receipt of the signal.
Local environments can also affect radio signals. Radio antennas placed inside cages metal or metal clad buildings can experience poor signal reception. In addition, the antennas located in a basement or underground may fail.
GPS uses the Global Positioning System for navigation worldwide. Each GPS satellite has on board a high-precision atomic clock sync – a ideal reference for NTP server synchronization.
GPS is a constellation of 24 satellites in orbit around each time continuous emission and positioning information. This information can be received anywhere on the face of the planet, providing an antenna can be provided with line of sight satellites.
GPS has a number of benefits over time based on radio frequency emissions. First, the GPS can be received anywhere in the world and is not limited by transmitter power and reach of the radio signal. Second, the GPS signal is a much more accurate than radio solutions. Third, when the GPS information can be received by anyone who can provide an antenna with a good view of the sky. However, GPS antennas need have line of sight with GPS satellites. Therefore, the ideal place for a GPS antenna is on a rooftop with a full 360 degree view of the sky. Also, if buildings or trees obscure the horizon anyway, can affect the integrity of receipt. Roof-mounted antennas can significantly add to costs Installation of a NTP server.
In summary, radio and GPS-based time and frequency references for NTP server systems both have certain advantages and disadvantages. However, the accuracy of GPS and receive guaranteed, even with roof-mounted antennas, make it the reference of choice for server systems NTP.
About the Author
Dave Evans is an experienced technical author with many years experience of NTP Server and Time Server systems and solutions to ensure accurate time on computers and network infrastructure. Dave has been heavily involved in the architecture of dedicated NTP time server systems, synchronised digital wall clocks and atomic clock timing products. Please visit our web site to find out more about time server and NTP Server systems.
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Time Signals, Including: Time Signal, Greenwich Time Signal, Rugby Radio Station, Anthorn Transmitting Station, Beta (Time Signal), Radio Reloj, Norddeich Station, Comparison of Time Signal Radio Stations, Noon Gun, Noonday Gun, 9 O’Clock Gun, Time Ball $14.57 New – Hephaestus Books represents a new publishing paradigm, allowing disparate content sources to be curated into cohesive, relevant, and informative books. To date, this content has been curated from Wikipedia articles and images under Creative Commons licensing, although as Hephaestus Books continues to increase in scope and dimension, more licensed and public domain content is being added. We believe books such as this represent a new and exciting lexicon in the sharing of human knowledge. T |
