17 4 Time and Frequency Transfer Fundamentals of Time and Frequency Transfer • Radio Time and Frequency Transfer Signals 17 5 Closing 17 1 Introduction Time and frequency standards supply three basic types of information: time-of-day, time interval, and frequency Time-of-day information is provided in hours, minutes, and seconds, but often
(380 deg ) one cycle event, the measured time from when it starts to when it ends, is the period A cycle measured in Hertz, is defined as 1 period per second (t) thus Frequency is the reciprocal of the time taken to complete one cycle f = 1/t Making frequency measurements, can be done using several methods, one is to beat one frequency
fundamental frequency value against the time at which the period took place A logarithmic scale is used to display Fx because it gives an approximate representation of the way in which we perceive pitch Distributions of fundamental frequency use can be calculated by building a histogram of excitation periods
frequency interval divider chain at the time of the 1988 ICAP conference [4] The plan was to measure the interval between a laser frequency and the second harmonic, which is equal to the laser frequency itself If this interval is repeatedly cut precisely in half, one will eventually reach a sufficiently small gap that can be measured as a
both time interval and frequency A second is defined as the time interval required for 9 192 631 770 transitions between two energy states of the cesium atom to take place The atomic definition of the second, together with current technology, allows it to be measured with much smaller uncertainties than any other SI unit
Time - Frequency Domain Time-Frequency analysis in principle captures both, but can also be harder to interpret allowing a map of frequency against time
which vary with time can be treated as SIGNALS and the value of the quantity against time signal by a sine wave at frequency f and integrating over all time