Masterclock NTP100 -SERIES - Utc;Greenwich Mean Time; NTP (Network Time Protocol); GPS Satellites (Model NTP100-GPS Only)

NTP100 – Rev 2.2.0 Oct-12
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UTC/Greenwich Mean Time
UTC is a time standard which is the basis for the worldwide system of civil time. This time scale is kept by time laboratories
around the world, including the U.S. Naval Observatory, and is determined using highly precise atomic clocks. The UTC
scale is coordinated in Paris by the International Bureau of Weights and Measures (BIPM).
UTC runs at the rate of the atomic clocks, but when the difference between this atomic time and one based on the Earth
approaches one second, a one second adjustment (a "leap second") is made in UTC.
UTC is the local time at the prime reference meridian at Greenwich, England. At a given location on the planet, local time
can be displaced (referenced to UTC) by -11 to +12 hours. North and South America are from -3 to -11 hours delayed; most
of Europe and Africa and all of Asia and Australia are advanced by +1 to +12 hours. Because the NTP time distribution
standard operates with UTC-reference time only, time zone and/or daylight savings (summer) time are not used.
UTC is sometimes colloquially referred to as "Greenwich Mean Time" (abbreviated GMT).
NTP (Network Time Protocol)
NTP is an open-standard time synchronization protocol designed for precision synchronization and maintenance of
time/date on computers and other devices attached to TCP/IP networks. NTP itself is transported with the UDP/IP
(User Datagram Protocol), and is usually served on port 123. NTP time/date is UTC-referenced, as the protocol has no
provisions for representing time zones or daylight savings (summer) time.
A wealth of useful NTP information and resources can be found at http://www.ntp.org
GPS Satellites (model NTP100-GPS only)
The GPS satellites are operated and maintained by the U.S. Department of Defense and allow for the precise determination of
local time and location at any point on (or above) the Earth. This is accomplished via the transmission of very accurate
timing information from a series of satellites that provide coverage of the entire planet.
The NTP100-GPS derives the precision UTC time that it serves from the GPS satellite network using an internal GPS
receiver and requires the connection of a pre-amplified GPS antenna.