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Even the Earth's rotation rate has more drift and variation in drift than an atomic clock due to tidal acceleration and other effects. The principle behind the atomic clock has enabled scientists to re-define the SI unit second in terms of exactly 9 192 631 770 oscillations of the caesium-133 atom. The precision of these oscillations allows ...
Clock synchronization is a topic in computer science and engineering that aims to coordinate otherwise independent clocks. Even when initially set accurately, real clocks will differ after some amount of time due to clock drift , caused by clocks counting time at slightly different rates.
The satellites' atomic clocks experience noise and clock drift errors. The navigation message contains corrections for these errors and estimates of the accuracy of the atomic clock. However, they are based on observations and may not indicate the clock's current state.
In electrical engineering, and particularly in telecommunications, frequency drift is an unintended and generally arbitrary offset of an oscillator from its nominal frequency. Causes may include component aging, [ 1 ] changes in temperature that alter the piezoelectric effect in a crystal oscillator , or problems with a voltage regulator which ...
During an interval of time τ, as measured by the reference clock, the clock under test advances by τy, where y is the average (relative) clock frequency over that interval. If we measure two consecutive intervals as shown, we can get a value of ( y − y ′ ) 2 —a smaller value indicates a more stable and precise clock.
The stored data are used to control phase and frequency variations, allowing the locked condition to be reproduced within specifications. Holdover begins when the clock output no longer reflects the influence of a connected external reference, or transition from it. Holdover terminates when the output of the clock reverts to locked mode condition.
With this method the average cancels out individual clock's tendencies to drift. Gusella and Zatti released results involving 15 computers whose clocks were synchronised to within about 20-25 milliseconds using their protocol. Computer systems normally avoid rewinding their clock when they receive a negative clock alteration from the leader.
There are two types of violation that can be caused by clock skew. One problem is caused when the clock reaches the first register and the clock signal towards the second register travels slower than output of the first register into the second register - the output of the first register reaches the second register input faster and therefore is clocked replacing the initial data on the second ...