1/f noise
1/f noise or pink noise is a mathematical equation that relates the power of the signal to the signal's frequency. A signal's power measurement will be 1/frequency, which is a power law relationship.
1/f Noise Media
A two-dimensional pink noise grayscale image, generated with a computer program; some fields observed in nature are characterized by a similar power spectrum
A 3D pink noise image, generated with a computer program, viewed as an animation in which each frame is a 2D slice
Relative intensity of pink noise (left) and white noise (right) on an FFT spectrogram with the vertical axis being linear frequency
The spatial filter which is convolved with a one-dimensional white noise signal to create a pink noise signal
A clock is most easily tested by comparing it with a far more accurate reference clock. 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.
\sigma^2(1) is approximately the area under the green curve; when \tau increases, S[g](\omega) shrinks on the x-axis, and the green curve shrinks on the x-axis but expands on the y-axis; when S[\dot x_f](\omega) \propto \omega^{-\alpha}, the combined effect of both is that \sigma^2(\tau) \propto \tau^{\alpha-1}
Noise curves for a selection of gravitational-wave detectors as a function of frequency
