| unbiased estimate of the preferred definition in the time domain of the short-term stability characteristic of the oscillator output frequency given by |
Yk are the average fractional frequency fluctuations obtained sequentially, with no systematic dead time between measurements;
τ is the sample time over which the measurements are averaged;
M is the number of measurements
Note 1 to entry: The confidence of the estimate improves as M increases.
Note 2 to entry: This entry was numbered 561-04-18 in IEC 60050-561:1991.